Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Term:

Settings

Beginner Intermediate Advanced No Definitions Definition Life:

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Comment Search Results

Search for hiatus

Comments matching the search hiatus:

More than 100 comments found. Only the most recent 100 have been displayed.

2023 SkS Weekly Climate Change & Global Warming News Roundup #44

MA Rodger at 10:04 AM on 11 November, 2023

Just Dean @22,

My apologies for misreading your comment @20.

The climatology community do not generally spend their time awaiting monthly global temperature anomalies and (as in the kerfuffle with the so-called 'hiatus' a decade back) tend to react to issues after they have arisen; and then not very fluently. So in that regard Jason Box is an oddity.

Concerning the contribution of El Niño to 2023 global temperatures, it is true that there were stronger La Niña conditions in mid-2022 than there was in mid-1996 and particularly in mid-2014. Thus the change from a cooling La Niña would perhaps suggest more resulting warming in 2023. But the flip side of that is the La Niña conditions so far in 2023 being far weaker than 1997 & 2016 suggesting less resulting warming. (Note the 2009-10 El Niño also began from strong La Niña conditions in 2008.) The net effect for 2023 should then perhaps be 1997 or 2015-like. But they are not.

Thus I would suggest there is ample evidence from the global temperature record to indicate something with perhaps even more warming impact on global temperatures than the coming La Niña.

If the temperature rise (using ERA5 with assumed Nov/Dec 2023 anomalies as per @21) the global temperature rise through the first year and then the additional second year rise run as follows:-
1996-97 ... +0.12ºC ... ... 1997-98 ... +0.19ºC
2008-09 ... +0.13ºC ... ... 2009-10 ... +0.10ºC
2014-15 ... +0.15ºC ... ... 2015-16 ... +0.18ºC
2022-23 ... +0.30ºC ... ... 2023-24 ... +???ºC

Perhaps it would be worth setting out the same data for was the most powerful El Niño of recent decades. This was overwhelmed by the El Chichón eruption of April 1982 which resulted in a cooling in 1982:-
1981-82 ... -0.20ºC ... ... 1982-83 ... +0.19ºC

So perhaps the Jan 2022 Hunga Tonga eruption and its water vapour is acting as a booster for 2023. (I mentioned satellite data @21 supporting this contention. See th 6 min video from Andrew Dessler here. It's now 3 months old.)

Ice age predicted in the 70s

Bob Loblaw at 07:17 AM on 19 August, 2023

MA Rodger @ 138:

Yes, this discussion is wandering off the blog post's topic. There is no way to determine Don Williamson's motives unless he explains them, but it appears that he is trying to do two things:

Take Oreskes' paper out of context to make it look like the 1970s "cooling" story was an indicator of a huge shift in climate science [it wasn't] - I presume to discredit climatology as a science [he hasn't].

Bootstrap the idea that "they don't know what they are talking about - they'll just make stuff up" by using the hiatus as an indicator that warming isn't linked to CO2 increases [he's wrong] and we might flip back into decades or centuries of cooling even if we burn every last bit of fossil fuels [we won't].

I have an off-topic challenge to Don that he has not yet responded to (review one example of the many "hiatus" papers he insinuates support him). I need to let him respond, if he is willing or able.

If the off-topic sound bites continue without responding to that challenge, I will probably need to bow out of the conversation and take on a moderator role.

Ice age predicted in the 70s

michael sweet at 00:36 AM on 19 August, 2023

Don Williams:

The "hiatus" papers do not show what you are claiming. Yes, Mann et al claimed that the "pause" was statistically significant. You can quote that paper. But in science it is not individual papers that count, it is the conclusions that count.

Foster and Ramsdorf replied to the Mann et al paper and claimed that the Mann et al paper had made calculation errors that invalidated their result. Foster et al claimed that there was no statistical significance. The scientific method is to exchange peer reviewed papers to debate facts. After several papers were exchanged, Mann et al conceded that they had made a mistake in their calculations and the "pause" was not statistically significant. It was magnificent to watch top scientists debate a fact and reach a consensus on what the true result was.

The scientific consensus is that the "pause" was simply random variation and not a change in the warmng pattern. Data collected since then have conclusively confirmed that the climate did not stop warming as demonstrated by the escalator. The Mann et al scientists agree with the consensus.

Mann and his collaborators are great scientists. Sometimes everyone makes mistakes. The difference between scientists and deniers is that when data shows that a scientist made a mistake they learn from the experience and move on. Deniers just regurgitate the same old debunked "pause" claims after everyone informed has moved on.

Ice age predicted in the 70s

MA Rodger at 00:33 AM on 19 August, 2023

Don Williamson @133 & others,
Discussion of the early 21st century SAT/SST record is hardily on-topic for this comment thread. The handful of years showing a reduced rate of warming surface tempertures did not lead to a reversal of warming but to an increased rate of warming, so any linkage to 1970's ideas of a coming ice age is entirely absent, despite an attempted linkage @108 up-thread. (And for the record, the take-away from the SciAm article referenced @133 is the ascribed response fro 'researchers' to all the 'hiatus' nonsense:-

"Picking a period of a decade or so where one part of the Earth's climate system fails to warm and using it to discredit all of climate science is a fallacious argument, and one driven by those with an agenda to discredit climate scientists."

Don Williamson, you have up-thread referenced Oreskes in the discussion of the 1970's idea of a coming ice age and insist there is some missing argument that gives continuing credibility to this 1970's idea (which are also ideas of earlier times according to Oreskes. "Throughout most of the history of science, geologists and geophysicists believed that Earth history was characterized by progressive, steady, cooling.") Do note the referenced pre-print conference paper does not constitute proof of a 'missing argument'. And were one sought, perhaps Oreskes (2007) 'The scientific consensus on climate change: How do we know we're not wrong?' can provide it.

Ice age predicted in the 70s

Bob Loblaw at 00:01 AM on 19 August, 2023

As a further part of the challenge to Don:

You have referred to "the hiatus". I will repeat the graphic of the Escalator:

The Escalator

Since the topic of the OP here is "cooling in the 1970s", and The Escalator shows seven periods of "no warming", please be specific as to which of those seven periods represents "the hiatus" you are talking about. Or a different period, if you have found an eighth.

Ice age predicted in the 70s

Bob Loblaw at 23:53 PM on 18 August, 2023

Don:

Just as I thought. You have not actually read any of the papers - you only have a link to something with selected quotes. And the "multiple papers" you claim are available just lead to Michael Mann mentioning a "temporary slowdown"?

I repeat my challenge:

Pick one - just one - of those papers, and provide us with a thorough review of that paper and how it supports your argument that the hiatus represents a serious challenge to the consensus position on anthropogenic increases in global temperature.

You're just blowing smoke.

Ice age predicted in the 70s

Don Williamson at 23:06 PM on 18 August, 2023

To Eclectic

Use Google Scholar as well as a couple of search engines reading peer-reviewed paper on the 'hiatus' 'wsrming slowdown'

If you jot down the various reasons that were used in the multiple papers you'll understand why Dr Michael E Mann said, "The problem isn't that we cannot explain the temporary slowdown in warming — ???????????? ???????????????????????????? ???????? ???????????????? ???????????????????? ???????????? ???????? ???????????????? ???????????????????????????????????????????????? ???????????? ????????"

Dr Kevin Trenberth Trenberth was a co-author on a paper published in Nature Climate Change that used models to show that pauses in surface temperature warming correspond to additional heat being stored deep in the ocean, ???????????????????? ???????????????????? ???????????????? ???????? ???????????? ???????????????????????????????? ???????????????????????????? ???????????????????????????????????? ????????????????????????????.

The 'warming' was taking place where there's little to no measuring devices?

Is that sound science?

link to quotes above:

https://www.scientificamerican.com/article/has-global-warming-paused/

????

Ice age predicted in the 70s

Bob Loblaw at 23:08 PM on 17 August, 2023

One more challenge for Don, which I predict will be ignored or deflected:

In comment #125 you mention that there are 100s of papers on the hiatus and claim:

...but I've done a lot of research into the hiatus - peer-reviewed papers 'research'

To demonstrate the level of "research" that you have done, here is the challenge:

Pick one - just one - of those papers, and provide us with a thorough review of that paper and how it supports your argument that the hiatus represents a serious challenge to the consensus position on anthropogenic increases in global temperature.

Don't forget to include a link to the paper.

Ice age predicted in the 70s

Bob Loblaw at 22:57 PM on 17 August, 2023

Frankly, Don, you are now reaching the point where you are just spouting bull$#!^.

I challenged you in comment #113 to provide two things:

State clearly what you think the "both sides" are.

State clearly who you think was a well-known climate scientist that was on "both sides".

You have not done this. You have just engaged in a game of "Look! Squirrel!" to jump to some other rhetorical talking point. You are playing games of "maybe this, maybe that" with no actual demonstration of understanding the physics of climate and what is likely or even reasonable possible. You have done selective quoting, and taking those quotes out of context, in order to try to show some grand disagreement or lack of understanding that does not exist.

The "abrupt about-face/reversal of opinion" that you are hanging your hat on is only "abrupt" if you refuse to look at the actual history of climate science and refuse to learn about the well-understood physics that explains the different observed trends and supports our understanding/interpretation. There is a term for that sort of refusal to look at the information available.

As Rob Honeycutt explains in #122, there has been no "reversal" in our understanding of orbital mechanics and long-term trends related to glacial/interglacial cycles. There has been no "reversal" in our understanding that CO2 is a greenhouse gas, and that greenhouse gases have a significant effect on global temperatures. There has been no "reversal" in our understanding that atmospheric aerosols (dust, soot, etc.) cause reductions in global surface temperatures.

What has changed is which of these factors is playing a dominant role in current temperature trends. CO2 is "winning", and it is winning rapidly.

You will probably come back with some sort of quip about "Oreskes said this". Well, the anti-evolution crowd is fond of claiming that Darwin said that evolution could not produce the eye. No, he didn't, and you are using the same rhetorical ploy in quoting Oreskes out of context.

You have now switched to shouting "hiatus!" from the treetops. Guess what? Climate science is interested in what factors affect these short-term variations in global temperatures. So, they study them in greater and greater detail (because instrumentation improves) each time they happen. And they happen on fairly regular intervals. So regular that you can track them by how often the contrarians need to update their "no warming since..." myths. Pretty soon, we're going to have to start to rebut "no warming since 2023", since 1998 2016 won't work any more:

Search/replace 1998

We even have a term for these "hiatus" events: we call it The Escalator. The graphic is in the right-hand margin of every SkS page, but here it is in full glory:

The Escalator

You keep saying "isn't this interesting?". No it is not interesting, it is tiresome. This site exists because some people refuse to learn the science and understand it. The "hiatus" was yet another temporary pause in one metric of global climate, and does nothing to reverse our expectations of future warming as CO2 continues to increase.

Your continued use of ":)" at the end of your comments suggests that you are now just trolling. (Gee. Isn't speculation without evidence just so much fun?)

Ice age predicted in the 70s

Eclectic at 13:02 PM on 17 August, 2023

Don Williamson @125 :

Agreed ~ 100s of peer-reviewed papers on the Hiatus subject of atmospheric pauses in [surface] temperature rise . . . but as Rob Honeycutt says: these pauses occur after every El Nino. Yet these are not actual pauses in modern global warming.

Do you understand the difference? And do you understand that none of us today should get too exercised about the topic?

Don , if the Hiatus is your own hobbyhorse, and you've done a lot of (internet?) research into the Hiatus . . . then you should be able to summarize its important points and place it in scientific context in today's perspective.

Ice age predicted in the 70s

Rob Honeycutt at 11:56 AM on 17 August, 2023

Don @123...

"One of the main thrusts of Ms Oresekes' article was the reversal of the dominant view - whether contrarians picked up on it or not."

And as I've attempted to explain repeatedly, there was a "reversal" because there was a "reversal" in the temperature trend. When it was cooling, the dominant position was that it was cooling. When the trend changed to warming, the dominant position "reversed" to warming.

I'm not sure why this fact escapes you.

"Why wouldn't 'this abrupt about-face—from cooling to warming' create doubt?"

Because it has nothing to do with any changes in the scientific understanding of forcings on the climate system that produce warming or cooling.

"A few years after the new consensus was formed - the hiatus made it's unfortunate debut."

Which was much ado about nothing. There's a "hiatus" after every major el nino event.

"I think I understand why people are interested in finding out why the abrupt about-face more than 'just accept the consensus because it's a consensus and we really mean it this time'"

Think about this:

We've known since the mid-1800's that CO2 is the primary radiatively active gas in the atmosphere. We've known since the early 1900's pretty much the amount of warming we'd see from a doubling of CO2 concentratations. Nothing has changed about that concensus, in fact it's only become vastly better understood since then.

The consensus that doubling CO2 would significantly warm the planet hasn't altered a bit. What Dr. Oreskes is speaking about is what was known about the temperature trend at the time, not the underlying physics of what was and is occurring.

Ice age predicted in the 70s

Don Williamson at 10:56 AM on 17 August, 2023

To Eclectic

The pause or slowdown was real, 100s of peer-reviewed papers on the subject so I don't think it was just someone's fantasy. There was a contributor to this website, he was cataloguing the papers. The last time I checked, which was a few years ago, he was expecting to top 300 papers on the subject. That's a lot of papers trying to explain a "talking point"

I can see that we'll have to agree to disagree but I've done a lot of research into the hiatus - peer-reviewed papers 'research'

Ice age predicted in the 70s

Eclectic at 10:39 AM on 17 August, 2023

Don Williamson @123 and prior :

To put things in a more realistic perspective : the Ocean Heat Content continued to rise during the so-called Hiatus of atmospheric temperatures. So there was actually no real Hiatus ~ it was just an interesting talking-point. The globe was continuing to warm.

Yes, we can discuss "the hiatus" as an abstract concept or as a propaganda topic ~ but we are wasting our time if we tie ourselves into a pretzel trying to argue about consensus or scientific opinion regarding a physical non-event in overall global warming.

Propaganda point: Yes . . . a real scientific point: No

However, the 1945-1975 "cooling pause" was definitely real.

Ice age predicted in the 70s

Don Williamson at 08:21 AM on 17 August, 2023

To Rob Honeycutt

One of the main thrusts of Ms Oresekes' article was the reversal of the dominant view - whether contrarians picked up on it or not.

Why wouldn't "this abrupt about-face—from cooling to warming" create doubt?

It seems logical to question the reversal especially when the climate scientists themselves reversed their opinion.

A few years after the new consensus was formed - the hiatus made it's unfortunate debut.

I think I understand why people are interested in finding out why the abrupt about-face more than 'just accept the consensus because it's a consensus and we really mean it this time''

Ice age predicted in the 70s

Don Williamson at 00:34 AM on 17 August, 2023

To Bob Loblaw

"unless we can give a convincing account of the empirical reasons behind that reversal"

I think we can agree the reversal was real. It needs to be explained by convincing arguments (rather that dismissing it out-of-hand) ~ but was that directed to the contrarians or to the "new consensus"?

The contrarians won't be convinced - they pounced on the flip flop as Ms Oreskes feared.

I think her article is a valuable insight into the innate complexities of climate science. The warming can taper off or cool. Maybe natural variability plates a bigger role that we might think?

Natural variability was a common refrain used in the hiatus discussions.

Ice age predicted in the 70s

Don Williamson at 12:30 PM on 16 August, 2023

Here's a great argument from Oreskes in her 2007 paper on the consensus.

"might the scientific consensus be wrong? If the history of science teaches anything, it’s humility. There are numerous historical examples where expert opinion turned out to be wrong"

The "cooling" was obviously in the data (some say cooling from the 1920s, some say cooling from the 1940s) but the warming eventually came to the forefront as Oreske stated in her 2004 article.

Will the warming continue? That can get into a very complex discussion about the hiatus - where many diverse opinions were offered. Some of the same scientists disputed and supported the reality of hiatus. Can cooling start again despite CO₂? We really don't know so locking in only one direction for temperatures leaves an opening for contrarians to pounce when it's not warming and they took advantage of that with the so-called hiatus. Some well known climate scientists were on both sides and that wasn't very helpful.

Climate Confusion

Doug Bostrom at 06:54 AM on 28 June, 2022

Confusion over "warming in the pipeline" reminds me a bit of the general confusion over the so-called "hiatus" observed in certain temperature records during whenever-to-whenever (1998-...?) any particular study showed a deceleration or halt of temperature rise.

There was never and could never be a "hiatus" in overall planetary warming short of a vast and mysterious disappearance of various GHG species, or some other impossibility. What appeared to be a slowdown or stall in warming to the extent this showed up in our metrics was (had to be) simply lack of perception on our part, incomplete instrumentation. There was no implausible change in radiative balance, sudden (and oddly unobserved) global albedo change or any other physical means of actually reducing the amount of energy accumulating on the planet. The energy was simply going where certain means of measurement couldn't see it.

But "hiatus" means a specific thing in the minds of most people, an actual pause in action.

"Warming in the pipeline" and "hiatus" are both examples of hastily conceived, poor terminology, sharing the feature of being mental pitfalls for information consumers of the normal, average variety.

Wildfires are not caused by global warming

Eclectic at 08:53 AM on 10 April, 2022

A-train1906 at post #4 :

Welcome back to this thread after your 18-month hiatus. (An enjoyable vacation, or a period of deep cogitation? )

It is indeed difficult to reach unambiguous conclusions about forest wildfires, because of the many confounding factors ~ and as you indicate, the forest understory (carbon buildup) is a major factor in fire intensity. ~Among other factors, like moisture levels and high temperatures.

To reach a scientifically valid conclusion, would require careful analysis of areas of untouched old-growth forests versus logged forests and plantations ~ of various degrees of management (including of the understory). So many variables, and so much room for gut-feelings to be wrong!

But either way, high temperatures and low moisture levels must be huge contributors to the problem, and are very evidently influenced by global warming. Clearly there is room for better forest management, and perhaps of novel types. Less clear, is whether that should include managed burns in virgin forests where (in previous centuries & millennia) the climate was cooler and/or wetter and where native peoples did not do burns.

All very difficult to assess (and react to). But we should not fall into the trap of implying that modern rapid global warming should be ignored.

A-train1906, there is a Youtube video by Potholer54 title from January 2020, titled: "The cause of Australia's bushfires _ what the SCIENCE says". Recommended. It is rather long, at 36 minutes . . . but Potholer54 does include some humorous parts, so it is all good entertainment as well ! It covers the catastrophic Australian fires only, but there are some general applications too.

SkS Analogy 22 - Energy SeaSaw

Bob Loblaw at 04:38 AM on 7 May, 2021

Evan:

"Is the record long enough?" is a characteristic of the data, not so much the method. A rule of thumb for global surface air temperature is that you need to have somewhere around 15-20 years of data to determine a trend - but that is deterimed from the noise characteristics of surface air temperature. It is not generally applicable to other data sets.

In addition to statistical significance, you also need to look at the power of the test. For a small trend, you need more data than for a large trend. With low power, a non-significant result may just be a lack of data, whereas if you have high power, no significant result is more likely to mean no relationship. Dikran Marsupial did a good post on this four years ago:

https://skepticalscience.com/statisticalsignificance.html

In addition to this, we are no longer in a position where the significance of our temperature trend is in question. We are clearly in a warming trend. When we encounter someone claiming "the warming has stopped!" or "No warming since 1998 2006 2010" (or whatever year they pick), asking if the trend is significantly different from zero is the wrong statistical test.

A statistical test involves evaluating the significance of the difference between "observed" and "expected". When testing if the trend is non-zero, the "expected" is zero. When testing if the existing trend has stopped, the "expected" value is the previous trend, not zero. So that is the comparison you need to make when determining something like a t-statistic.

So, to try to directly answer your question, any 10-year period should be looked at in the context of what preceded it. For the "warming stopped in..." argument, the easiest statement to make would be to say "the last 10 years shows the trend continuing".

The Foster and Rahmstorf paper that KR mentions is very good. Foster is the person that writes https://tamino.wordpress.com/, where you will find lots of excellent posts on statistics and climate (He's been on hiatus for while now, but the archives are a treasure-trove of good stuff.)

The approach taken in the Foster and Rahmstorf paper is to quantify known sources of variation and remove them from the data, leaving the long-term trend showing clearly. If you leave that variation in, it is treated as unidentified noise in a regression, which makes the trend harder to see. (It would be wrong to reduce the noise by averaging - that just deceives the regression test. You need to be able to independently say "yes this causes variation and I know how much".)

...and we always can make use of the SkS Escalator image:

The Escalator

Critical Thinking about Climate - a video series by John Cook

Eclectic at 10:08 AM on 8 October, 2020

Nigelj, in general you are correct about "sceptics" revising their previous position ~ when finally all the world and his wife are pointing the finger of scorn & reproach.

That would be so for the milder cases of climate denialism, over the next 20 years, I expect. But not so much for the hard-core denialists (you know the type) . . . they use a seemingly-infinite amount of motivated reasoning to resist the reality which is staring them in the face.

For the hard-core cases, the "noisiness" of data over the coming decades ~ will be a hook for their every hope. Every pause/hiatus in surface temperature, every brief uptick in arctic sea-ice extent, every season which happens to be rather quieter in hurricanes / wildfires / sea-level-rise . . . every example will be pointed to as a fore-runner of the coming Cooling Century which will confound the mainstream scientists.

These cases are the hard-core denialists who will maintain their position . . . right up until they themselves fall to the final sweep of the Reaper's Scythe.

It hasn't warmed since 1998

sailingfree at 08:45 AM on 12 September, 2020

to Philippe at 405:

Thank you so much for the updated temperature plot. It is the best "Hiatus Killer" I've seen.

For years I have been waiting to see the SKS escalator brought up to date, showing 2019.

Hansen's 1988 prediction was wrong

MA Rodger at 20:24 PM on 3 July, 2020

Nylo @58/59/60,

I don't see that I can agree with any of that.

Note the primary source of CH4 levels is NOAA ESRL and these provide global data from 1983 although this record was not established as such until the 1990s. Thus you will note that Hansen et al (1988) references Lacis et al (1981) for its CH4 data. And this reference should give a bit of a warning that something is amiss with the passage from Hansen et al Appendix B that you quote.

Lacis et al describe the rise in CH4 1970-80 as being 150ppb, from 1.5ppm to 1.65ppm.

And there is evidently an error in Appendix B of Hansen et al. We have two alternative errors, one a simple typo (although an error nonetheless) and the other one a careless omission with massively significant implications. (i) Either the error was that the "1.4ppbv" should have read "1.4ppmv" = 1,400ppbv. (ii) Or the value "1.4ppbv" for 1958 which CH4 "increases from" is meant to be the start value of a rate-of-increase rising by a set percentage per year. If this were the case, it should have read "1.4ppbv per year in 1958".

It is evident from Lacis et al that the corrected version is "1.4ppmv". Using percentage increases set out in Hansen et al, the "1.4ppmv" start-point in yields a 1970-80 CH4 level running from 1504ppb to 1670ppb.

The alternative appears a tiny bit ridiculous as, if Hansen et al did work with CH4 based on "1.4ppbv per year in 1958" it would require both a profoundly mistaken reading of Lacis et al and an egregious miscalculation of the forcing resulting from the vastly reduced rise in CH4 levels. That is, CH4 rise would total 20ppb 1980-90 rather than the 270ppb using the "1.4ppm". (Modern estimates/measurements yield 220ppb 1980-90.) If you examine Figb1, an increase of 1.6ppm CH4 yields 0.16ΔTo(ºC) which pro rata would yield from Figb2's 0.0295ΔTo(ºC) a 1980's decadal CH4 rise of 295ppb, a finding which is wholly incompatible with the adoption of a 20ppb decadal increase.

....

Concerning the CH4 'hiatus' of the early 2000s, the deceleration in the atmospheric CH4 rise was spotted by the early 1990s and its cause (a reduction in anthropogenic emissions) was understood before 2010 (although which anthropogenic source wasn't clear), as was the obvious signs if it ending.

Hansen's 1988 prediction was wrong

MA Rodger at 20:19 PM on 2 July, 2020

Nylo @53,

The graph Fig 1 of the 'basic' OP above without the post-2016 GISS data does indeed suggest a more robust record of warming than would be the case with 2017-19 data added, but I wouldn't go so far as to describe it as being "a very red and tasty cherry". The climate forcing 1988-to-date is a little short of Scenario B and so also is the trend in global temperature. (GISS data relative to 2016, the following years sit 0.09ºC, 0.17ºC, 0.04ºC below 2016 with 2020 potentially topping 2016.)

Regarding the forcings relative to 1988, Fig 4 of the 'advanced' OP above plots 'actual' relative to the scenarios of Hansen et al. These derive from annual emissions of all anthropogenic forcings as does the 1.5% you quote for Hansen et al for Scenario A. The paper's Appendix B describes in more detail the acceleration in emissions for the various gases in Scenario A and the tailing-off that accelerations in Scenario B.

I'm not sure you are describing this change in annual emissions.

I suspect you are looking at either accumulative CO2 emissions since pre-industrial times (an increase of 69% since 1988) or solely annual FF CO2 emissions (an increase of 67% although that is reduced to 57% if LUC CO2 emissions are included). The numbers I quote are calcuated from Global Carbon Project data.

The NOAA AGGI gives the annual forcing data from GHG emissions which shows today's annual increase in forcing is slightly reduced relative to 1988 (this the net effect of increasing CO2 emissions balanced by the drop in CFC emissions and the 'hiatus' in CH4 emissions). In more detail, the annual forcing increase dropped from the 1980s into the 1990s but has since been on the rise again. So the forcing accounted in the AGGI are running below the Hansen et al Scenarion B but AGGI does not include any change in negative forcing from aerosols which will have boosted net forcing a bit over the period (as shown in that Fig 4 of the OP).

How deniers maintain the consensus gap

Eclectic at 12:05 PM on 24 February, 2020

JoeZ , I am pleased to see you have returned to multiple-thread posting at SkS after a brief "hiatus". Perhaps you were confused when you said that SkepticalScience had given you "a warning that ... [you would] be locked out!" . I haven't seen any evidence of such a warning ~ so presumably it came on some other website where you currently post.

Readers at SkS like to see science and fact-based opinions, rather than mere truculent denialism. So I am hoping you can provide some reasonable comment on the scientific consensus, even when you are struggling to come to terms with the future spending of "trillions" of dollars in dealing with the global warming problem. ( I would be interested to see - on another thread, please - a more precise budgeting of your projected "trillions". Trillions [over 30 years] are sometimes a figure thrown about, but AFAIK they are not offset by the trillions that would otherwise ordinarily be spent on upgrading & routine replacement of coal-fired power stations, and the routine replacement of ICE cars & so on, and on medical health costs & loss of productivity from air-pollution/particulates, nor the high [dollar] costs associated with big numbers of climate refugees . . . going to Boston etcetera. Nor the many other costs arising from a warming world. Human compassion aside, for those who are purely concerned with the dollar bottom-line, it seems a bargain to spend up-front money in tackling climate change.

.... and a minor comparison, the APPA expenditure figures project a total spend [over 30 years] of one trillion dollars on pet food. And that's just for the USA, alone. )

The five corrupt pillars of climate change denial

BillyJoe at 10:01 AM on 25 December, 2019

blub:

"The models are not robust at all between about 2000-2015"

Didn't you mean 1998-2012? In any case, you are cherry-picking. Why did you not comment on the entire record? Is it because the entire record shows that the models are indeed robust. At the very least, because of natural cycles, you have to look at a minimum 30 year intervals in order to see the signal from the noise. By picking 1998-2012, you are looking at the noise, not the signal, which is obvious if you look at the entire record.

"but have been recalibrated because of the heating hiatus"

No, there is no evidence for any recalibration at all between 1998 and 2012. If you disagree please show your evidence and your references.

"This is far from settled science"

When we say "settled science" we don't mean every detail is settled, only that certain details are settled. And "settled" means that "the vast majority of climate scientists agree that an assessemnt of all the evidence leads to this conclusion". As examples: CO2 is increasing, global tempertures are increasing, anthropogenic sources are almost entirely responsible for the increase in CO2, adverse overall climate consequences are already happening and will get worse especially if we go above 1.5 degrees C. This is all "settled science".

"only a handful of "real" climatologists..even understand climate modeling correctly".

There are not just a "handful" of "real" climatologists who understand climate modeling correctly, and those who do agree that the models are robust. As in every field there are contrarians, and those with fringe on climate science who disagree.

The rest of your comment consists, likewise, of cherry-picked links. This is not how science is done. All the papers and all the evidence must be taken into account. This is what the IPCC does and you should avail yourself of the conclusions contained in their reports or distilled by reputable science communicators.

The five corrupt pillars of climate change denial

nigelj at 06:00 AM on 25 December, 2019

blub @1

"The models are not robust at all between about 2000-2015, but have been recalibrated because of the heating hiatus during this time. This is far from settled science, but only a handful of "real" climatologists not self proclaimed climate scientists even understand climate modeling correctly."

Adding a few things. Climate models can never be 100% robust over short time frames of about 15 years, because these timeframes are modulated by ocean variability, and this does not follow a completely regular cycle. For blubs information, you cant ever accurately predict something that is partly random. Climate models are intended to model long terms trends of 30 years and more, and do this well. Scientists are aware of natural variability and the very first IPCC reports stated there would be flat periods within a longer term warming trend. The slowdown after 1998 was such a flat period.

Blub claims models have been recalibrated, but provides no evidence of this.

Blubs claims about a handful of so called real climate scientists are totally unsubstantiated arm waving.

Regarding the rest of his screed on natural variability. Cherrypicking a couple of scientific papers does not demonstrate anything. Nothing is provided to show there has been wide acceptance of these specific papers, and they do not falsify any of the models.

Models do reproduce ocean cycles, although not perfectly. However models have proven to have good accuracy at predicting multiple trends including temperatures here and here. Clearly although ocean cycles are not perfectly understood, their affects are overwhelmed by CO2.

The five corrupt pillars of climate change denial

KingInYellow at 23:13 PM on 24 December, 2019

The models are not robust at all between about 2000-2015, but have been recalibrated because of the heating hiatus during this time.

Climate is measured over a minimum of 30 years. This ddefinition was arrived at in 1934 by the IMO.

This is due to the internal variables - the natural cycles - t hat were already known of back then.

Just because we do not know everything, does not mean we know nothing.

Science advances incrementally, and the recalibration of the models so they can project shorter poeriods both globally and locally is an example of progress, not uncertainty.

All the best.

The five corrupt pillars of climate change denial

blub at 18:09 PM on 24 December, 2019

"All these arguments are false and there is a clear consensus among scientists about the causes of climate change. The climate models that predict global temperature rises have remained very similar over the last 30 years despite the huge increase in complexity, showing it is a robust outcome of the science."

The models are not robust at all between about 2000-2015, but have been recalibrated because of the heating hiatus during this time. This is far from settled science, but only a handful of "real" climatologists not self proclaimed climate scientists even understand climate modeling correctly.

The fast majority of scientists and I would assume public knows that is warming and CO2 has some influence, but it’s the warming cause is not understood entirely and therefore model predictions may be erroneous.
The following links took me 30min of researching:
https://link.springer.com/article/10.1007%2Fs00704-018-2387-7
Quantifying the importance of interannual, interdecadal and multidecadal climate natural variabilities in the modulation of global warming rates.
https://link.springer.com/article/10.1007/s00382-019-04955-2?shared-article-renderer#ref-CR12

Author: Essentially, this work emphasizes the vital role of natural variability in changing the local linear trends which represent the warming rates of corresponding periods. Our results imply that to rightly attribute the climate change and accurately forecast future climate, more attention should be paid to various quasi-periodic natural variabilities, particularly ones at interannual, interdecadal and multidecadal scales. Of upmost importance, the key points to improve the simulation and prediction skills of climate models lie in correctly distinguishing the true anthropogenic warming from natural variability and accurately simulating the phase, period and amplitude of important natural variability, in which the phase is particularly important. Unfortunately, even the state-of-the-art CMIP5 models still confuse the natural climate variability and the anthropogenic warming trend and show low skills for natural variability simulations, which is the primary cause that they fail to simulate the recent global warming hiatus (Wei and Qiao 2017).

Models are not missing something or are they?:
Evidence that global evapotranspiration makes a substantial contribution to the global atmospheric temperature slowdown
https://link.springer.com/article/10.1007%2Fs00704-018-2387-7

A greening world enhances the surface-air temperature difference
https://www.sciencedirect.com/science/article/pii/S0048969718350733?via%3Dihub

Here Are 3 Climategate Myths That Have Not Aged Well

One Planet Only Forever at 09:19 AM on 1 December, 2019

nyood @20,

Others have already provided accurate responses.

I wish to add my own 'improvement of the awareness and understanding' to help you appreciate the accurate context and perspective.

You claim I missed the point of your comment because your "... concern was that the hiatus is considered to be something bad by some authors of the emails. It does not need any skeptic here, it is the authors themselfs, hence the terms pschology and political thinking. ... It is about considering good news (less warming) as bad news. Despite of all poralization one would hope that these scientists still want the best for humanity and not see cooling as a problem."

The reason for concerns by climate scientists regarding short-term less rapid temperature rise (hiatus) or short-term cooling is that the they are only short-term events in the temperature data. However, each one is claimed by the worst of the skeptics to be proof that the warming has ended and the science is wrong.

It is almost as bad to try to claim that concerns about any of the many short-term reductions in the rate of temperature rise due to added CO2 in the atmosphere are wrong because 'cooling is Good'.

The Escalator I pointed you to in my earlier comment should have made that clear. Either it was not obvious to you, or you never checked it out. To be clearer, in the escalator it can be seen that at the end of each 'hiatus or cooling event that you claim everyone should be thrilled to see', there is a dramatic step up to the start of the next 'hiatus or cooling event that you claim everyone should be thrilled to see'. Can you see how anyone more aware and understanding of what is really going on would not be Thrilled?

Sustainable Cooling would indeed be Good. But the science is clear that that will only happen if the levels of CO2, and other human generated ghgs, in the atmosphere are reduced. And the reduction of CO2 is almost certain to only happen when the use of fossil fuels is ended.

And until the use of fossil fuels is ended the CO2 and other ghgs will continue to increase. And the science is clear that a 1.5 C total warming is the point beyond which the climate impacts can be very severe. Even a 2.0 C warming is likely to be very hard on the future generations.

And as michael sweet has pointed out there has already been more than 1.0 C of warming with the CO2 only at 410 ppm (a 140 ppm increase from pre-industrial) but is currently rising at more than 20 ppm per decade.

Any claim to see "A cooling trend in the temperature data" without a reduction of CO2 is "Claiming False Hope" (now and in the past), and deserves the be corrected. And promoters of the harmful fictional claims deserve to be ridiculed if they persist in unethically resisting becoming more aware and better understanding.

Here Are 3 Climategate Myths That Have Not Aged Well

nyood at 21:21 PM on 30 November, 2019

One Planet Only Forever @18

You are missing the point. My concern was that the hiatus is considered to be something bad by some authors of the emails. It does not need any skeptic here, it is the authors themselfs, hence the terms pschology and political thinking.

So it is not about skeptics abusing the hiatus.

It is not about reasoning why the haitus happened.

It is about considering good news (less warming) as bad news.

Despite of all poralization one would hope that these scientists still want the best for humanity and not see cooling as a problem.

If skeptics wish that it will be colder, just because they are "more" right is demasking, almost childish.

If the IPCC wishes it will get warmer or stay hot, just because they will be right is demasking and reduces integrity.

Here Are 3 Climategate Myths That Have Not Aged Well

One Planet Only Forever at 12:29 PM on 30 November, 2019

nyood @10,

It is very polarizing indeed to still see people still make claims like: "And other sentences make you wonder why a cooling or hiatus is considered to be a problem, instead of a relief when it comes towards warming as a threat."

The trend of the temperature record is undeniable. The existence of variations in the short-term rate of warming is abundantly clear. The skeptics harmfully abusing any period of slower temperature change to reduce popular support for the required Responsible Leadership Actions are definitely deserving of derision (not praise for relieving concern).

Refer to the SkS Escalator.

Here Are 3 Climategate Myths That Have Not Aged Well

nyood at 05:12 AM on 29 November, 2019

To me Climategate is about the psychology and about the casual conversation within East Anglia, nothing more but nothing less.

Climategate is not about scientific fraud to me, I am aware of the quotes taken out of context as a cheap trick on the far skeptical side and I am aware that there is in general, some ferocity in the operating language of such an institute. I can also follow the antagonistic attitude to an extent, since the attacks by skeptics are not always fair and go on for decades now.

However, as an every man lay when you come in contact with these leaked emails for the first time, it makes you really wonder why there is such a severe hostility towards skeptics. And other sentences make you wonder why a cooling or hiatus is considered to be a problem, instead of a relief when it comes towards warming as a threat.

The language used in these emails is concerning, they are very political and extremely polarized to a point where it makes one wonder if it is still possible for the authors to keep a scientific neutrality.

As I am not sure if quoting emails is allowed here, I will not risk to quote any, if it is within the policy of SkepticalScience please tell me, then we could talk about some examples which highlight political thinking and involuntary confessions.

2019 SkS Weekly Climate Change & Global Warming News Roundup #40

nigelj at 08:02 AM on 7 October, 2019

The five: Donald Trump’s attacks on science.

The US president is a climate-crisis denier, but it is not the only field in which he is at odds with scientists and their work

Last week, a report by US campaign group the National Task Force on Rule of Law and Democracy, compiled by ex-government officials, concluded that under the Trump administration that there were now “almost weekly violations” to the impartiality of scientific research.

Conservation cut

In April the Trump administration withdrew funding for the Landscape Conservation Cooperatives, a large and successful conservation programme that tackled issues such as the climate crisis, species extinction and energy security. Sixteen of the original 22 research centres have now been dissolved or are on an indefinite “hiatus”. This was in defiance of instructions from Congress, which had approved $12.5m of federal funding for the cooperatives.

Weather blackout

Donald Trump’s government has refused to publicise dozens of studies from the US Department of Agriculture that examine the impact of the climate crisis. Agriculture secretary, Sonny Perdue, has previously expressed scepticism about climate change, believing it to simply be due to “weather patterns”.

Climate censorship

In June, it was reported that the White House had tried to stop Dr Rod Schoonover, a senior intelligence analyst, from discussing climate change when delivering congressional testimony. The reason given was that the science was not aligned with the views of the Trump administration.

Short-term approach

James Reilly, the director of the US Geological Survey (USGS), has ordered that scientific assessments produced by USGS use climate models that only track the possible impact of climate change until 2040, rather than until the end of the century, as they had done previously. The second half of the century is likely to see the most dramatic impacts of global heating.

There are genuine climate alarmists, but they're not in the same league as deniers

Postkey at 17:43 PM on 8 September, 2019

” . . . Actually, we show that aerosol-induced cooling is currently only ~0.4°C (see 3rd figure in the CarbonBrief article). Higher aerosol sensitivity would be incompatible with the observed mid-century hiatus. Plus, current warming would be overestimated if transient sensitivity was higher than we report. The neat thing is that the temporal evolution of (warming) anthropogenic greenhouse gases and (cooling) aerosols is not a mirror image. Hence they can both be constrained fairly robustly now.”www.realclimate.org/index.php/archives/2019/06/unforced-variations-vs-forced-responses/#comments

Arctic icemelt is a natural cycle

MA Rodger at 18:59 PM on 20 June, 2019

With the absence of any further comment from commenter bruce, it might be worthwhile joining a few dots to make sense of his intervention @70.

The insistence that Arcric SIE annual minimums have "not decreased since 2007" follows from denialist insistence that there has been an Arctic version of the 'hiatus' - Arctic Sea Ice has not been diminishing as it did in previous AGW years and the trend is now flat. Swart et ak (2015) 'Influence of internal variability on Arctic sea-ice trends' has been cited as showing evidence of this 'hiatus' operating over the 6-year period 2007-13 and which is now assertedly extended for significantly more years. Thus the "not decreased since 2007" is not interested in the 2012 minimum as the denialist assertion concerns the multi-year trend not the individual years.

The data used for IPCC FAR Fig20 is described thus:-

"Sea-ice conditions are now reported regularly in marine synoptic observations, as well as by special reconnaissance flights, and coastal radar. Especially importantly, satellite observations have been used to map sea-ice extent routinelysince the early 1970s.The American Navy Joint Ice Center has produced weekly charts which have been digitised by NOAA. These data are summarized in Figure 7.20 which is based on analyses carried out on a 1°latitude x 2.5° longitude grid."

It is obviously not the best of data given it shows such a small drop in SIE 1979-1990. It may be possible to find this data within literature of the time (the likes of say Mysak & Manak (1998) also use some JIC data) but it doesn't in anyway resemble modern satellite SIE data.

The AMO's "close correlation with Arctic ice" is probably simple nonsense. Even denialists like Connolly et al (2017) found it difficult to fabricate an Arctic SIE racord based on Arctic temperature that was much different to more respectable records using similar methods. The graphic below is from Cea-Pirón & Cano-Pasalodos presented within a Judith Curry blog-comment-thread. SIE records such as HadISST & Marsh et al (2016) developed from historical ice records show significantly higher SIE over the earlier pre-1950 years, perhaps 2M sq km higher. None of these show any AMO-like wobbles.

Arctic SIE based on temperature

But what Connolly et al did manage to achieve was to present a graphic to the world (below) from Alekseev et al (2016) [paywalled] (but without the actual post-1979 SIE data plotted as in Alekseev et al (2015) Fig3b) and without mentioning the finding predicting of an ice-free Arctic summers by 2030.
Alekseev et al Fig

If you are happy with the most basic of similarities being considered as being a "close correlation", the likes of this Alekseev et al (2016) graph may be assumed as an upside-down AMO graph but the assertion doesn't actually pass muster. Firstly the Alekseev et al graph is simply an upside-down version of a rather crude Arctic summer temperature record which are then no more than assumed as a proxy for Arctic summer SIE minimums. And even then, the upside-down AMO does have a very different shape. The 1950 AMO(us-d) was the same value as recent values with a peak inbetween in the 1970s (rather than 1960s) and a 'hiatus' since 1999. So AMO(us-d) is a long way off from being a proxy for Arctic SIE values.

The temperature evolution after 2016 suggests hotter future

MA Rodger at 21:28 PM on 19 March, 2019

ThinkingMan @17,

The concept of a natural unforced climate cycle is part of the denialist armoury and is usually presented as a 60-year cycle. I think it gets lengthened to allow more abiguity when fitting it to data.

The sole basis of it is the global temperature record which can been seem as having peaks in 1880, 1940 & 2000 and dips in 1910 & 1970. Thus a 60-year cycle is proposed as causing these peaks and dips.

Hadley global temperature

Those proposing the existence of such a 60-year natural cycle have failed to take the idea forward. Further the peaks and dips can be understood without the existence of some grand natural wobble.

Thus the so-called 'hiatus' of recent years can be explained by the impact of ENSO which is a natural wobble-maker. Yet such a natural wobble does not explain the slight cooling post-1940. This has more to do with a slowing of AGW positive forcings through those years and a massive increase in the rate of anthropogenic SO2 emissions. The 1940 peak is more of a challenge but over half of it results from forcing, most of this anthropogenic. And back to the 1880 dip, the volcanism during the latter part of the 19th century easily privide the dip without any 60-year wobble.

Another approach to finding a 60-year wobble is to seek evidence for the wobble within the known natural oscillation. As set out above, ENSO (& thus PDO) are not powerful enough to be a source of the size of wobble being talked about. One other candidate is AMO mentioned @16. AMO is an interesting phenomenon. It was fisrt identified within a proxy reconstruction of North Atlantic temperatures. This were part of the work that resulted in the famous 'hockeystick' reconstruction of Northern Hemisphere temperatures. And here's a thing - the AMO is not seen in the 'hockeystick', suggesting it too has not the power to provide a significant 60-year global wobble (IPCC AR5 also demonstrate the lack of power) although there is much work now showing the AMO is a true oscillation of roughly 60-year pitch.

2019 SkS Weekly Climate Change & Global Warming News Roundup #11

citizenschallenge at 10:44 AM on 19 March, 2019

Who's kidding whom, this handwringing about tornado trends is nothing but cyncial political score keeping intend on distractiung. Just like that ludicrous obsession with the nonexistant "global warming hiatus." That's politics in action not science, even though it deeply impacts science.

I did read it all - and again just now for you. It spends more time focusing on uncertainties, lossing the opportunity to explain some fundamentals. Of course, it's all accurate, I'm not disputing that.

It's the messaging that fails, as it has for decades! You may not admit it, but words in that FactCheck were all about playing second-fiddle to the contrarian storyline, rather than taking the moment to refocus on the important stuff. But, no, instead, repeat it, underscore it, get lost in more details that fly by people's heads - because the headline will have already told them all they need to know:

'oh still no connection between tornadoes and global warming. When will the climate scientists finally figure out this global warming thing?

Please, the worst part of those write ups, none of them helped convey any fundamental gut level understanding of what our global heat and moisture distribution is all about.

Perhaps it wouldn't be the worst for you to read with a bit less prejudgementn yourself - and a bit more attention on what I've actually written?

My question:

Why continue spending our time focusing on the inconsequential uncertainties, while ignoring the huge certainties and what they have to tell us for certain.

Why not actively steer the dialogue alway from the cynical distractions and back to the real world basic fundamentals that few seem to grasp.

I invite you to show me where my above statement is factually wrong? I'll take any lesson you want to teach me.

______________________________________

Here's an offering for you, a different perspective perhaps, but definately based on down to Earth facts as revealed by science and learned about over a life time.

a) Who says understanding Earth’s Evolution is irrelevant? 2018

d) Considering our dysfunctional public dialogue in 14 verses.

e) Map v Territory Problem, Statistical Certainty vs Geophysical Realities

also -

https://confrontingsciencecontrarians.blogspot.com/2018/12/the-missing-key-gould.html

The temperature evolution after 2016 suggests hotter future

Ari Jokimäki at 00:58 AM on 19 March, 2019

The 60-80 year cycle refers to AMO/AMV, I think. One of the first papers discussing it was Schlesinger & Ramankutty (1994): An oscillation in the global climate system of period 65-70 years. See also my paperlist on the subject.

At least one of the hiatus papers (in the paper sample of our paper 1 linked in the post above) mentions that there was a switch to cooling in Atlantic at around 1995. There aree some other papers also that discuss the role of Atlantic relating to the global warming hiatus. I think the answer to ThinkingMan is that the cooling phase might already have made an appearance but in the presence of long term warming, it doesn't show so clearly in the global mean surface temperature. While AMO's effect is strong around Atlantic, it's effect to GMST might not be so strong.

The temperature evolution after 2016 suggests hotter future

ThinkingMan at 03:26 AM on 18 March, 2019

Rather than debate again & again the hiatus or slower warming issue, I respectfully suggest researching & discussing a related issue. Has anthropogenic warming offset natural cooling forces since 2000 or so?

The annual average global temperature has NOT trended downwards since 2000, 2015 or some year in between. EVERYONE concedes this point. One might reasonably expect a downwards trend since then because of a routine, recurring, widely acknowledged 60-80 temperature cycle. The cycle's most recent warming phase started 1970-1975, or so. The cooling phase should have started 30-40 years later, which would place the start date between 2000 & 2015.

So, why has the cooling phase NOT made an appearance? The answer should profoundly influence expectations for climate.

The temperature evolution after 2016 suggests hotter future

John Hartz at 01:06 AM on 13 March, 2019

Recommended supplemental reading:

Missing Arctic temperature data, not Mother Nature, created the seeming slowdown of global warming from 1998 to 2012, according to a new study in the journal Nature Climate Change.

A University of Alaska Fairbanks professor and his colleagues in China constructed the first data set of surface temperatures from across the world that significantly improves representation of the Arctic during the "global warming hiatus."

Xiangdong Zhang, an atmospheric scientist with UAF's International Arctic Research Center, said he collaborated with colleagues at Tsinghua University in Beijing and Chinese agencies studying Arctic warming to analyze temperature data collected from buoys drifting in the Arctic Ocean.

"We recalculated the average global temperatures from 1998-2012 and found that the rate of global warming had continued to rise at 0.112C per decade instead of slowing down to 0.05C per decade as previously thought," said Zhang.

The new data also improved estimates of the global warming and the Arctic warming rate.

Added Arctic data shows global warming didn't pause, Phys.org, Nov 20, 2017

Sea level rise is exaggerated

Eclectic at 19:42 PM on 15 November, 2017

There are: misrepresentations, damned misrepresentations, and statistics !

Oh, where is our Disraeli or our Churchill when we need him, eh NorrisM. Churchill, I am sure, would make short work of Koonin and Koonin's misrepresentations — and Churchill would use a three-letter word, not a polysyllabic.

In particular for Koonin's statement on SLR's . . . "The rates since 1993 are at the high end of this range, but are not statistically different from those during the first half of the 20th Century." ~ That being the sort of weasel statistics up with which Churchill would not put.

"Not statistically different" is a term we have heard before — during the transient "Hiatus" in surface temperatures during the Noughties of this Century. ~ A pseudo-analysis by science-denialists, which deliberately and clearly ignored the vast weight of evidence [ocean warming] and ignored the most basic physical processes [CO2/GHG effect] still going on unabated. It was a phrase which sailed very close to, but not quite over the edge of . . . damned misrepresentation. It was designed to pull the wool over the eyes of the casual reader who did not bother to think it through, and who had little climate knowledge.

And now [stated October 2017] Koonin is saying sea-level rise for the 21st Century is as yet not statistically different from earlier times. He ignores the fact that the 1940-ish SLR "bump" was a small and minor variation from the background rising trend, and was quite a different kettle of fish from the high/accelerating rise of recent decades (which has very clear causation by ongoing thermal expansion of the ocean and by large-scale ongoing melting of land-based ice sheets. And Koonin makes his statements despite having the hindsight from (late) 2017.

Such misrepresentation by Koonin (for a man of considerable scientific ability) could not be accidental or unintentional. Indeed, it is all one, with the typical science-denier strategy of continual misrepresentation of what is really happening in our physical world, in regard to AGW. Rather obviously, Koonin is wishing to imply to the casual reader, that Global Warming is non-existent or of minimal importance.

# NorrisM, there is no need for you to reply to my post here. Koonin seems to be on a long campaign of various misrepresentations . . . and I am reasonably sure there is nothing you could say to redeem his current reputation.

We should move on, to the pure science of sea-level rise where of course [re your post #265] there's a small difference of figures from satellite and tide-gauge measurements — since they are measuring two slightly different things [not different by much: but coastal measurements can never be exactly the same as "coastal + mid ocean" ].

Climate and energy are becoming focal points in state political races

NorrisM at 14:17 PM on 31 October, 2017

michael sweet @ 184

I appreciate that the IPCC 2013 assessment is based upon the information at that time. Here is what the summary says:

"It is very likely that the global mean rate was 1.7 [1.5 to 1.9] mm yr–1 between 1901 and 2010 for a total sea level rise of 0.19 [0.17 to 0.21] m. Between 1993 and 2010, the rate was very likely higher at 3.2 [2.8 to 3.6] mm yr–1; similarly high rates likely occurred between 1920 and 1950. {3.7.2, 3.7.4, 5.6.3, 13.2.1, 13.2.2, Figure 13.3}"

Until the IPCC reexamines all of the papers at its next assessment, it seems reasonable to assume that we are around 3.2 mm/yr but knowing that things logically could accelerate assuming that the temperature does increase as projected. Attempting to use averages over a 5 year period seems to be problematic in the same way that arguments were made relating to the well-known 10-13 year "hiatus". On this very graph above, the rate of increase seems to have levelled off after the El Nino was finished.

It is interesting that in the above IPCC quote we had similar "high rates" during the period 1920-1950. Curious as to whether there is any explanation of that anomaly.

Climate and energy are becoming focal points in state political races

NorrisM at 17:24 PM on 22 October, 2017

Bob Loblaw @ 143

I have been very impressed by your arguments generally (interesting to see two Canadians go at it). But this comment really distorts what I have said and sounds like some others which look for some "underlying preconceived notions".

A few examples:

"Just because you want to label uncertainties in these costs as "vague", "theoretical", etc. does not mean that the best estimate of these additional costs is $0."

I have never said that the best estimate of the additional costs is $0. What I have said is that you will not get the US, Europe or China onside to recognize this because of the costs to their particular society in imposing some carbon tax beyond pollution costs. Of course, the future costs are much more than the pure "pollution costs". But unless you have a very easy alternative (as to costs and viability), then you have to weigh the benefits of FF to the future costs. I have already indicated what I think should be a two-pronged approach.

"That you keep repeating shop-worn denier talking points about uncertainty, models, etc. suggests that at some deep level you are still believing or hoping that the science is all wrong and no significant change is needed."

Wrong. It has nothing to do with hoping the science is all wrong. I also do not thing the science is all wrong. But my concern with the models, especially after having read a very honest Chapter 9 of the IPCC 2013 Assessment during my recent holiday, is that I do not think that we have the ability to model, by computers, the complexities of the climate to a level that we can fully trust them. I am not saying that the models are useless, but when I read in the IPCC assessment that the models have been "tuned" to match reality in "hindcasts" (in ways not disclosed to the IPCC) then it raises serious questions as to the ability of models to predict the future 50 years from now and suggest that sea levels really will increase at rates much higher than present levels. I understand that any model would have to be adjusted in hindsight to input things like actual volcanic activity and actual El Ninos and other actual ocean oscillations but my sense is that with these "adjustments" we are not much better off than taking a ruler and projecting sea level and temperature rises based upon the last 25-50 years.

That is why I have found myself reverting to what is actually happening both as to average temperature increases and average sea level rises over X period of years. I think it is eminently reasonable to assume, in the absence of evidence to the contrary, that things will continue at the same rates as we have seen. We had a "hiatus" for a period of 12-15 years in average temperature rise but I am more than prepared to accept that this was a "blip" and that temperatures will continue to rise because the CO2 emissions continue.

At 71 years of age, I am not concerned about myself or my economic position. I am concerned about the world but I am, more than anything, a realist. I have two adult children who will have to live in this world (I actually worry that there are other things that are more dangerous to their future welfare than climate change). So when I advocate things, I take into account political realities together with a general skepticism that we as humans are apocalyptic. Just remember that climate scientists in the 1970's, or at least a fair number, were suggesting we were on our way to another mini ice age. I just do not think that we are about to go over Niagara Falls. We have some time to see if this really is a problem. For at least 25 years, we have been told we were going "over the cliff" (or over the waterfall) and it has not happened.

I am happy to deal with linear increases. If we find that "linear' is in fact wrong, then we deal with it. That is why I have been trying to sort out what the actual sea level rise has been for the last 25 years.

The other thing I have not mentioned is my question as to whether the CO2 emissions will be the same over the next 30 years with BAU as it has been for the last 30 years. China has taken massive steps using cheap coal to fuel its industrialization. Hopefully this will not go on for the next 30 years. Surely they will not again "double" their existing steel production. Clearly China will be using wind and solar (in conjunction with their existing coal plants) to mitigate their pollution costs. As I type this, it has occurred to me that China is not focussing on nuclear power. I have never heard this from any of the commentators but that is probably one of the best arguments that nuclear power does not make economic sense. If a planned economy like China has not moved to nuclear power (and the Chinese are no dummies) then there are reasons that argue for wind and solar in favour of nuclear (I still find this disappointing for our world - I saw some of the wind farms in Spain). For some they are pretty, but to me it is a sad commentary on what humans are doing to the world.

My point is that you misrepresent my concerns. They are not based upon some "head in the sand" approach. But at least I think you would agree that I am entitled to express my opinions and that I should not be shuffled off to jail or fined for expressing them.

The Mail's censure shows which media outlets are biased on climate change

nigelj at 07:05 AM on 1 October, 2017

MA Rodger @40

"She will raises issues but almost always fails to set out clearly what she concludes from such issues."

This has also been my exact same impression of various things she has said. Its very frustrating and it creates enormous doubts, exactly what climate denialists deliberately set out to do, so she plays right into their hands, either deliberately or unwittingly.

I think going back to your previous post all the trouble started when she was heavily criticised over her research paper on weather systems. It appears she lost confidence in herself, or something, and started to side with the sceptics and perhaps their was some genuine desire to respect their point of view, or at least listen to it, at least at first. But its a slippery slope, and she is a full scale denialist now whether she realises it or not, and admits it or not. Her rhetoric speaks for itself. It reminds me of the theme expressed in the book Animal Farm by Orwell.

"Her evidence on the relevance of the 'hiatus' never concludes. Rather it rambles on about "The growing discrepancy between climate model predictions and the observations".

Exactly. Now at that point in time of her testimony it was fair to say temperatures were falling towards the lower boundary of error bars, but they were not outside these and as far as I'm aware its always been predicted you could have approx. 10 year periods of slow temperature growth, or even falling temperatures due to a variety of natural cycles. Curry must know that so why didn't she say so in her testimony? If she thinks natural causes could not have been responsible for the "pause", then why does she not say so? By saying nothing, she is unbalanced and not fulsome in her testimony, and can only be seen as a full on climate denialist whether she intends this or not.

"and for good measure the graph stops short of the latest 2015 warmth),'

Again Curry must have know this, and it puts her testimony into the frankly misleading category. This is not good enough.

"we need to look at the satellite data. I mean, this is the best data that we have and is global")".

I'm just gobsmacked by this, as again she must know the limitations of this data. Its certainly not the best data. Again it puts her fully in the Watts Up denialist camp, and is the exact sort of rhetoric they use. She is copying and pasting what they say.

You dont need to have a degree in atmospheric physics to know that none of the data sets are 100% perfect, and the sane and sensible thing to do would be to take an average of them all. Curry is qualified and obviously very intelligent, so something has become unhinged somewhere, to be saying the things she is saying.

I have no problem with scepticism as its natural, and I dont take things at face value, but I think we have a duty to be balanced and tell things in full context, and explain a full conclusion, and Curry does neither of these things.

"Yes, I do believe that we have overall been warming, but we have been warming for 200, maybe even 400 years, OK? And that is not caused by humans."

This just feeds right into the denialist machine. She has been suckered in. And clearly theres a big acceleration in warming form 1920 so why doesn't she see the significance of that?

"the land datasets are sort of starting to agree"

She is thinking aloud. You do this in private with colleagues not when testifying to politicians! She doesnt know when to shut up.

The Mail's censure shows which media outlets are biased on climate change

MA Rodger at 21:36 PM on 30 September, 2017

nigelJ @39,
Note that within her spreading of doubt and denial about AGW, Curry is even happy to trash the temperature record. (This is perhaps odd as the temperature record is about the only thing she has to base her grand theory of there being a humongous natural climate wobble which has amplified the recent AGW over 1970-98 to create the present climate 'hysteria' with Wyatt's Unified Wave Theory being Judy's candidate for such an oscillation back in 2015.)

Her stance in the temperature record is basically that 'there has been warming, but...' with the 'but' being followed by the buckets of doubt and denial. In many ways her comments about the temperature-record exemplifies her highly unscientific method. She will raises issues but almost always fails to set out clearly what she concludes from such issues. If she did, she would be slammed for promulgating serious denial with sky-high Monckton-ratings.

Consider her testemony about the temperature record in front of this 2015 Senate Committee:-
♠ Her citing of the hockeystick graph as showing "overall warming may have occurred for the past 300–400 years. Humans contributed little if anything to this early global warming," rather misrepresents the hockeystick. She is strongly suggesting that the possible 0.2ºC warming over a recent 300-year period (1600-1900) somehow brings into serious doubt the IPCC's attribution of the 1.2ºC warming since 1900.
♠ Her evidence on the relevance of the 'hiatus' never concludes. Rather it rambles on about "The growing discrepancy between climate model predictions and the observations", the raging debates over the recent Karl et al (2015), the 'hiatus' "clearly revealed" by satellite data (helpfully plotted by denialist Roy Spencer so the graph shows the now-superceded RSSv3.3 and the then-yet-to-be-released UAHv6.0 and with the RSS data re-based and curiously shorn of some of its maxs&mins and for good measure the graph stops short of the latest 2015 warmth), scientific disagreement over discrepancies between TLT & SAT records (and note where she stands on that with her oral testimony "we need to look at the satellite data. I mean, this is the best data that we have and is global"), convoluted statistical probability of 2015 becoming warmest-year-on-record, discrepancies amongst temperature data sets, a five years requirement to be sure the 'hiatus' has actually ended. It rambles on but the relevance of the 'hiatus', the message she is meant to be delivering, is never set out.
♠ Beyond her written testimony, Curry also expounds on SAT record adjustments, spreading yet more doubt:-

"... And the adjustments, as you can see, are rather huge, OK?
So should we—so, to me, the error bars should really be much bigger if they are making such a large adjustment. So we really don’t know too much about what is going on in terms of, you know, it is a great deal of uncertainty. Yes, I do believe that we have overall been warming, but we have been warming for 200, maybe even 400 years, OK? And that is not caused by humans."

After the digression onto the pet "warming for even 400 years,OK" Curry returns to adjustments but specifically ocean adjustments stating "I mean, the land datasets are sort of starting to agree, but there is a great deal of controversy and uncertainty right now in the treatment of the ocean temperatures." Poor Judy has failed to note that Chariman Cruz was asking for comment on USCHN data adjustments and her comment relevant to that data solely comprises "the land datasets are sort of starting to agree" and thus that the adjustments Cruz is complaining about are perfectly appropriate. Yet that is certainly not the take-away message she provides.

Curry gets away with talking this rubbish, even in written reports presented to a Senate Committe. She really should be taken to task for it.

The Mail's censure shows which media outlets are biased on climate change

Tom13 at 00:04 AM on 28 September, 2017

#24 eclectic

(A) in April 2015 : "Recent data and research supports the importance of natural climate variability and calls into question the conclusion that humans are the dominant cause of recent climate change" (unquote)

A reasonable acknowledgement that natural causes play a significant role (perhaps dominant role ) in climate change - to deny otherwise is anti science.

(B) also in 2015 at a Congressional hearing, she stated about the global warming [of the past 200 years] : "And that's not human" (unquote)

Do you have a citation and the full statement - the 4 word quote ilacks the full context of her statement.

(C) in 2014 speaking at the National Press Club : "We just don't know [what's going to happen]. I think we are fooling ourselves to think that CO2 control knob really influences climate on these decadal or even century time scales." (unquote)

A reasonable acknowledgement that Co2 may not play the dominant role which is consistent with the earth's past history. Note that not once does her statement say that CO2 is not a factor.

(D) in November 2015 [please specially note this very recent date, Randman] she supported the existence of the so-called hiatus or pause : "global average surface temperature ... has shown little or no warming during the 21st century" (unquote)

Based on the scientific data available at that time, this is a reasonably accurate statement. While the 2015/2016 el nino started in early summer of 2015, the data showing showing a more than a little warming since 1998 wasnt strong until very early 2016.

(E) in 2011, she supported Murry Salby's crazy/nonsensical "hypothesis" that oceanic-origin CO2 is the real cause of our modern rapid Global Warming.

Ths statement seems completely out of context with her other statements and writings. J curry has repeatedly stated that the oceans play a key role in climate change and has repeatedly stated that OHC will play a huge role future climate change, including the build up of ohc.

The Mail's censure shows which media outlets are biased on climate change

Eclectic at 20:59 PM on 27 September, 2017

Randman @22 , about your quote: "she was" (unquote)

She was . . . what? What are you talking about? Please be precise! Readers here don't wish to bother second-guessing what you intend to mean.

Regarding Judith Curry :- the sources are her own comments :

(A) in April 2015 : "Recent data and research supports the importance of natural climate variability and calls into question the conclusion that humans are the dominant cause of recent climate change" (unquote)

(B) also in 2015 at a Congressional hearing, she stated about the global warming [of the past 200 years] : "And that's not human" (unquote)

(C) in 2014 speaking at the National Press Club : "We just don't know [what's going to happen]. I think we are fooling ourselves to think that CO2 control knob really influences climate on these decadal or even century time scales." (unquote)

(D) in November 2015 [please specially note this very recent date, Randman] she supported the existence of the so-called hiatus or pause : "global average surface temperature ... has shown little or no warming during the 21st century" (unquote)

(E) in 2011, she supported Murry Salby's crazy/nonsensical "hypothesis" that oceanic-origin CO2 is the real cause of our modern rapid Global Warming.

Now, Randman, consider each of the above 5 statements. If you yourself had issued them, then it would be evidence that you were grossly ignorant about climate science. If they had been made by a scientist (a scientist not specializing in climate related matters), then that would count as intellectual dishonesty. Issued by a climatologist, that would rise to the level of gross intellectual dishonesty.

Individually, each of the above statements cannot be justified, for they are individually & severally false and/or misleading. Randman, I could add others to the list . . . but (to paraphrase an Einstein quote) :- "It only takes one" !

$$$$$$$

Randman, I do not in any way suggest that Curry receives money illegally from the Oil industry & other anti-science propagandists. Arguably, what money or other benefits she receives from such groups is immoral but not illegal.

~ In 2006, Judith Curry [climatologist] and Peter Webster [meteorologist] set up a private company "Climate Forecast Applications Network". Judith Curry is President (not an unpaid job, I gather!). Curry herself said (in an interview with Scientific American) : "I do receive some funding from the fossil fuel industry ... [per my company] since 2007." (unquote). Please note, Randman, that that sort of thing is not illegal — it is simply one of the many ways that the Oil industry slush funds operate.

Perhaps you are innocently unaware, Randman, that the fossil fuel industry slush fund money percolates all around the place. [Though I had to laugh when I saw that Peabody Energy's filing for bankruptcy in 2016 had "stiffed" the prominent science-denier Richard Lindzen, for a USD$25,000 "consultancy fee" that they owed him — though I don't know whether that $25,000 was a one-off or an annual stipend.] Stipends, expenses, etc are paid in various ways — sometimes by "sinecure" payments, sometimes by propaganda "fronts" like Heartland or GWPF, sometimes by other under-the-counter indirect methods e.g. payments to a company (not to the individual).

As to other benefits [in non-monetary form, not in cash] there are the examples of Curry appearing at least three times in front of Congressional-level hearings. I am sure that even you, Randman, are not so naive as to believe that Curry paid for travel accommodation & incidental expenses, out of her own purse — if you act as a prominent stooge for Big Corporations, then they look after you in the premium style. That's just the way the business world is, Randman. (But it's not in any way illegal for her to be on the Big Oil teat.) And then there's the purely psychological benefits she receives — definitely an ego boost for a mediocre climate scientist, to appear (and often) in the national Congressional limelight (etc).

Then there are other benefits in cash e.g. in January and February this year [her academic retirement onto a teacher's pension, being at the end of December 2016] Judith Curry authored two reports, one for Koch Brothers and one for the British propaganda machine GWPF. I don't know whether she was paid directly into her personal account or indirectly via her CFAN company, or by other means — but it would have been a generous*-sized benefit. Again, not illegal — but of doubtful morality. ( *Randman, it is extremely difficult for denialism-pushing Big Corporations to find any scientist with more than a shred of repectability/reputation who can be relied on as a stooge who will play the "Doubt & Uncertainty" game, in the face of all the overwhelming evidence that proves "D&U" is unjustified/dishonest.)

In Summary :

So, all in all, Randman, your own phrasing: "her scientific reasoning is dishonest, biased and she is funded by the oil companies" . . . is a fairly good summation of the situation.

Temp record is unreliable

randman at 08:42 AM on 25 September, 2017

Tom, this is the paper by Hansen with 288 Kelvin as the mean. I think you've already seen the press comments by Hansen and Jones in 1988 of 59 degrees F and "roughly 59 degrees" respectively, right?

LINK

Obviously regardless of looking at anomalies, there is a reason they believed the mean was 59 degrees. The fact climatologists like to look at anomalies does not change that, does it? Not seeing your point.

On a wider note, this appears to be a pattern. 15 degrees was later adjusted down to 14 degrees, which had the effect of making the then present temps appear warmer, whether correctly so or not.

More recently, we've seen satellite data that showed no sea level rise to speak of "adjusted", perhaps correctly so or not, to now show sea level rise.

http://www.nature.com/news/satellite-snafu-masked-true-sea-level-rise-for-decades-1.22312

Prior to that we saw the posited warming hiatus changed by some, which changes including lowering the past means among other things. One climatologists somewhat famously has complained about this, Judith Curry. Some of her comments here:

""This short paper in Science is not adequate to explain and explore the very large changes that have been made to the NOAA data set," she wrote. "The global surface temperature data sets are clearly a moving target. So while I'm sure this latest analysis from NOAA will be regarded as politically useful for the Obama Administration, I don't regard it as a particularly useful contribution to our scientific understanding of what is going on.""

http://news.nationalgeographic.com/2015/06/150604-hiatus-climate-warming-temperature-denier-NOAA/

https://judithcurry.com/2015/07/09/recent-hiatus-caused-by-decadal-shift-in-indo-pacific-heating-2/

As I understand it, Curry was a proponent of AGW and perhaps still is in some respect, but has had problems with the way the data has been adjusted and the accuracy of the models among other things.

She's not the only scientist raises these questions. So it's not just laymen like myself who wonder why there appears to be a pattern of data that does not line up with predictions simply being "adjusted." These adjustments are not just one-off things either but a fairly consistent feature here.

The Trump administration wants to bail out failed contrarian climate scientists

Bob Loblaw at 03:43 AM on 5 September, 2017

NorrisM:

I just read through the Koonin document you linked to. It is full of vague, incorrect, and rhetorical contrivances. They may appear "reasonable" to someone that does not know the science, but it is not a good summary of the science.

Koonin's statement:

"My training as a computational physicist - together with a 40-year career of scientific research, advising and management in academia, government and the private sector - has afforded me an extended, up-close perspective on climate science.

...is exactly the sort of false claim of expertise that I reject in comments 34 and 44.

How the hiatus affects our understanding of climate is grossly overblown by the denial side of this discussion. Yes, it provides an interesting observation to help us understand short-term variability, but it has not lasted and the long-term trend continues (as evidenced by the pasts few years). That the IPCC reflected on it is direct evidence against the idea that the science ignores these things.

A Red Team/Blue Team exercise, where the rules are made by a biased group, and the evaluation will be led by a biased group, will have a zero chance at uncovering any "truth". You've said you have a legal background. How would you feel arguing a case in court when the other lawyer and the judge were old school mates, with no legal training, and they got to make up the rules under which the case was to be tried?

The Trump administration wants to bail out failed contrarian climate scientists

NorrisM at 02:39 AM on 5 September, 2017

scaddenp @ 39

Thanks. My purpose was not to get into a discussion of MWP but rather to discuss what might be part of an exchange of information as part of a Red Team Blue Team process. But talk about a "Rabbit hole". That blog seems to have a higher fever pitch than any other!

Bob Loblaw @ 44

Yes I have read Andy Lacis' comments and in fact reread them. I read them and they made a lot of sense. Then somehow I was directed to a summary by Koonin of his WSJ article this spring. I read it and it made a lot of sense. At least take a look at it here. http://cusp.nyu.edu/wp-content/uploads/2014/09/Climate-article-annotated1.pdf

What strikes me is that reading these two discussions tells me that for someone with a non-scientific background, it is a hopeless case to "research" this area and come up with a view.

It is for that very reason that I would dearly love to hear the experts directly contradict each other in some form of "give and take" so you are not just listening to one side and then the other. You deal with each statement as it is made.

I understand why you would not want Koonin as the sole chair of such an exchange. He himself has suggested Co-Chairs and perhaps that is the way to go. Koonin on one side and a representative of the "warmists" (for lack of a better term) on the other side. I am not using the term "scientific consensus side" or similar term because we are not talking about whether the current warming is primarily caused by man where there is (largely) a consensus but disagreements on what the effects on temperature will be.

But I have to admit there were two things that made me at least question the warmist position. They were : 1. IPCC's acknowledgment of a "hiatus" in their 2013 Assessment; and 2. Reading the transcript of the APS investigation that was chaired by Koonin. I have elsewhere made the point that the IPCC climatologists had their chance to strongly state their case and they seemed to have admitted that their models were not matching observations. By the way, I did notice the first time I read that transcript that Koonin's expression of "surprise" about the uncertainty in the models surprised me in that he had to have formed the group who wrote up the Framework Document. So the "surprise" had to be a little feigned. But it does not change the response by the IPCC climatologists.

A Red Team Blue Team would be the chance for Warmists to make their case to the American public.

Surrendering to fear brought us climate change denial and President Trump

ubrew12 at 05:37 AM on 18 July, 2017

If this is fear, then good news on non-fossil energy is the antidote. It may do more to emphasize the enormous strides being made in renewable power lately, than to prove conclusively to someone immune to proof that the 'hiatus' never happened.

Big fossils likes to preach its captive audience that if they go with alternatives, the 'big government gulags' will not be far behind. Stories that tell the truth may matter here: that alternatives are largely being fought by utilities which, as government-granted monopolies, are the very epitome of 'big government'. It should sway some minds to realize that Joe Libertarian, in fighting renewable power, is fighting on the same side as a state-sponsored monopoly that thinks it 'owns' the right to sell him electricity, to the exclusion of all other sources in an open market.

Why the Republican Party's climate policy obstruction is indefensible

Bob Loblaw at 11:20 AM on 11 July, 2017

NorrisM:

In your fourth paragraph, you pose two questions that indicate you still are not recognizing what global climate models can and cannot do. Let me try to provide some sort of explanation.

The first question is If the models are capable of predicting the future then they should have had an answer for the supposed "hiatus"

But the models are not capable of predicting short term variability, such as El Nino events. They do have El Nino events, but the timing is more or less random and does not match the exact sequence of a particular set of years. Different model runs with slightly different starting conditions will place El Nino events at different times.

Thus, you can't use the timing of El Ninos and related temperatures to test model skill. If El Ninos are simulated with a similar frequency and magnitude as the real world, then the model has skill even though the timing isn't exact.

Let us take a non-climate model of a familar concept as an analogy: tossing a coin. With a fair coin, there is a 50:50 chance of heads or tails with each toss, and I will model a sequence of ten tosses using a spreadsheet with a random number generator. I will repeat the model simulation 9 times. Here are the sequences, with the counts of heads and tails:

HHTTTTHHTT 4 6
TTHHTHTTTT 3 7
TTHHHHHTHH 7 3
HHHHHHTTTT 6 4
THHTTTTHTT 3 7
THHTTTHHTT 4 6
TTTTHTTHTH 3 7
HHHTTHTHTT 5 5
HTHTHTTTTH 4 6
TTHHTTTHTH 4 6

Now, you may notice that there are 10 sequences, not nine. I also did one real coin toss sequence, and generated one more random number to decide where to place it in the order. One of the above ten sequences is real; the other nine are modelled.

Note that none of the sequences are the same - therefore none of the model sequences exactly matches the real sequence. You cannot conclude from this that the model is wrong, however. It may be, but you can't tell that from this data.

Can you identify the real sequence? If not, then the nine modelled sequences are realistic enough to pass this sniff test. And with the global temperature record, we can have many model runs but only one real sequence, just as I have done with the coin tosses.

On to question 2: "If the physics explain this 25 year increase in temperatures (1975-1998), how do you explain the temperature increases and decreases that I had referenced earlier, especially the .3C rise from 1900 - 1940 or so."

The earlier period is more difficult to deal with because we do not have sufficient data to force the models - measurements of essential variables such as radiation, atmospheric dust, etc. were fewer and less accurate.

Again, I will use simple analogy with a simple model.

My model says that A + B = C.
Today, I know that A = 3.03 and B = 7.64, and that C = 10.71, with all values uncertain to +/-0.05.
My model predicts that C = 10.67 today, with an uncertainty of +/-0.07 (because of the uncertainty in A and B). My model is 0.04 off the known value of C, but within the error bars of both my estimate and the measurement.
In the past, A was 4.1 and B was 3.7, both with uncertainties of +/-0.5. The model says C would be 7.8+/-0.7.
The known value of C was 8.5+/-0.05. The model error of 0.7 is not necessarily due to a poor measurement of C or a poor model, however - it could be due to the lack of knowledge of the input values A and B. The error is larger, but the uncertainty bounds are also larger.
I could play with the values of A and B to get better agreement, but there is little point. Without a time machine to go back and get better measurements, I would not know if the better agreement is because I got a better value with a good model, or whether I just managed to get the errors in A and B to offset the errors in the model.

Does this clarify what can and cannot be done with a (climate) model?

Why the Republican Party's climate policy obstruction is indefensible

scaddenp at 10:50 AM on 11 July, 2017

NorrisM - " If the models are capable of predicting the future then they should have had an answer for the supposed "hiatus" "

You are still not grasping the point I already stated that the models have limitations on what they predict and in particular have a/ no skill at decadal prediction and b/ dont pretend too. Model evaluation is subject of chp9 of the IPCC report. If you want to know the answers to your questions, then try reading it. Insisting model predict what they catagorically state they cannot is denier rhetorical ploy.

Mid-century cooling is discussed on this site here.

Why the Republican Party's climate policy obstruction is indefensible

NorrisM at 09:16 AM on 11 July, 2017

Thanks for the comments on my last post. My apologies to Tom Curtis for attributing the comment re Koonin to him. Eclectic your comment was not vicious in any sense but I do think we should stick to what people say and not who they are (although I have to admit if anyone has some "strong fundamentalist religious leanings" I cannot help but put a tick mark against anything else they say even though it may be completely rational).

This morning at home when I opened this website, the reply of Andy Laicy (sp) to Koonin opened in front of me magically. It was a detailed answer to the short questions I had posed relating to the "hard physics" which had been answered in short fashion by Tom Curtis (I had only asked for yes no answers at the time). Laicy's reply is pretty understandable even for a layman. So this explains the solid science based upon physics.

So there is a rational explanation that makes sense to most scientists whether they be climate scientists or other scientists.

So the question comes down to whether, using this science incorporated into a GCM, you can then actually predict the future. As a layman, the two things that puzzled me after being initially convinced by the Dessler book was: 1. If the models are capable of predicting the future then they should have had an answer for the supposed "hiatus" and 2. If the physics explain this 25 year increase in temperatures (1975-1998), how do you explain the temperature increases and decreases that I had referenced earlier, especially the .3C rise from 1900 - 1940 or so.

But for now, I would like to concentrate on what I believe is the "discrepancy" that Christy has proposed based upon his diagram. What surprises was the passive reaction of Santer and Held when questioned by Koonin about Christy's diagram. They made references to some studies that had examined this discrepancy in the past but did not comment on their conclusions nor did they strongly object to what Christy was alleging. Surely, if the difference was only marginal that they would have said so at that time. It was absolutely basic to their case.

I guess this "basic to their case" is another question. What has really troubled me is if you cannot reconcile major differences with the models and observations (if that is the case) then how can you still believe that we are still in the 3C range rather than 1-1.5C by 2100? Is this where Hawking and other non-climate scientists are? To them, is it irrelevant that the models are not sophisticated enough to predict the future? Or does it all come down to position that the models are predicting things?

In other words, does the case for anthropogenic warming of 3C stand or fall on the models? If not, then why?

But, I have to say, even if we are so sure that this period of warming was caused by humans, then surely there still has to be a full answer for why the temperature went up from 1900 to 1940. For me, notwithstanding Michael Mann's hockey stick, I would also like to have some explanation for the MWP (even his most recent graph seems to acknowledge this warming). But it would go a long way to at least have a rational explanation for the warming in the first 40 years of the 20th century.

I suspect that the answer to the model discrepancy is that it is a small discrepancy. But if this is the case, then why did Santer and Held not say so when they had the golden opportunity, knowing that the transcript of the APS hearing would effectively be read by the world.

To SkepticalScience Editor: I saw one attempt to "reconstruct" the Christy diagram but it was very confusing continually flashing from one thing to another. Could you not do a "simple" reconstruction showing where the "red line" should be and where the "blue dots" should be. Leave out the "ranges" just as Christy did or perhaps have three lines, High, Medium and Low Case. It would be very helpful.

Why the Republican Party's climate policy obstruction is indefensible

ubrew12 at 02:33 AM on 7 July, 2017

NorrisM@6 said: "ClimateGate had a very damaging effect... It is very similar to evidence given by a witness testifying in some legal case... For any jury, ALL of the evidence of that witness is tainted."

I'm constantly amazed how often climate deniers use the Law as an example to Science. Who has a more questionable reputation, lawyers or scientists? Next time I see a scientist chasing an ambulance I'll revise my opinion. For example, deniers keep harping on the exact timing of the demise of the Arctic summer sea ice. It is apparently really, really important to them that the scientists accurately predict the exact year when Arctic summer sea ice disappears. Who, other than a lawyer, performs this kind of misdirection? Hey, prosecutor, 80% of the sea ice is already gone! Past tense. In the last 30 years. Outside a courtroom, is there any question where the remaining 20% is headed?

Those of us fighting what is going on need to be aware that we are fighting rooms full of lawyers, and their speciality is misdirection. A favorite is 'moving the goalposts': like suddenly its no longer sufficient to point out that 80% of Arctic summer sea ice is gone, scientists must now predict exactly when the remaining 20% will be gone or their reputations will be ruined, their testimony tainted, and climate denial justified for the rest of eternity.

The appeal to jurisprudence is how NorrisM can point to the 'hiatus' and render judgement, "The models did not predict this and therefore are unreliable." But barrister, outside the kind of courtroom that found OJ Simpson guiltless of murder, any model of reality fundamentally cannot beat reality. It's not possible. It can only beat other models. It's not the fault of scientists if the Heartland Institute won't produce any. What you really should be asking yourself, NorrisM, is: 'Why won't they?'. That would at least lead you to a constructive outcome.

Why the Republican Party's climate policy obstruction is indefensible

nigelj at 18:44 PM on 6 July, 2017

Norris M @6

Interesting comments, but I largely disagree.

"Rightly or wrongly, I think that ClimateGate had a very damaging effect on the climate change views of conservatives everywhere. "

Well it probably didn't help their views. I can appreciate that much.

People do get tainted by one so called mistake (alleged in the cause of climategate), but that is very shallow to dismiss people on that basis.

It's also very much "wrongly" that climate gate tainted anyones views. I'm a political moderate, with a reasonably decent arts, technical and some science education. It only took me five minutes reading the actual evidence of climate gate and both sides of debate and commentary, to see there was literally nothing there, nothing wrong. Numerous investigations have also concluded the same.

People concluding otherwise, must want to conclude otherwise, and are being irrational. I do however agree it was an unfortuante thing and rather bad luck, but to claim it means the damage is irreversible is absurd, innacurate and lazy thinking.

"Judith Curry has herself admitted that this made her seriously question her position which was until then "mainstream"

Her views are in a small minority of climate scientists, and she does not have a spectacular research record or any great clarity on anything, in fact she is rather vague about things. So please explain why you give her views prominence.

"The hiatus"

So much rubbish is talked about this. Firstly the latest information shows the pause was more of a short blip, and entirely within expectations. Last years temperatures changed everything.

It's at least partly inaccurate to claim models didn't predict the pause. All models without exception expect flat periods, but its impossible to predict them exacly because short term natural variation is slightly random. Models have been reasonably reliable predicting temperatures, as evidenced by articles on this website.

Things are still slightly under predictions, but only slightly and this is not enough to be concerned about. Republicans dont appear to want to hear that, instead they seem to hear, things are not 100% as predicted to within millimetres, so everything must be wrong. With respect this is childish, self interested, and intellectually empty thinking, and they are smarter than that.

"For now let us not get into arguments about this because you will NOT convince the Republicans by one "new study" that shows that the IPCC was mistaken. "

So you are saying don't even try because people are so stubborn with minds closed? Humanity might as well give up. Just imagine your outrage if Hilary Clinton said something like that. Nobody needs to be that closed minded.

Remember the only evidence that really counts is the science, and weight of scientific evidence, and it all points one way. Not politics, or character of climate scientists, or scandals, or occasional mistakes, or the like. One mistake on a minor point does not make an entire theory wrong, or key conclusions wrong. Climate change theory is built on wide evidence, not one piece of evidence.

"So "97% of climate scientists" does not cut it with Republicans. They simply do not trust the climate scientists believing, rightly or wrongly, that their bread and butter is really based upon making sure that climate change is primarily man-made."

Well that is just foolish thinking. Scientists are not exaggerating to manufacture work. Scientists get work in all sorts of fields because its needed, without glamourising everything.

We could turn around and say we dont trust politicians because their bread and butter depends on xyz, or business people or anyone. The world cannot and doesn't work like that or it would come to a complete stop . You have to have fundamental trust in professionals, unless they personally start to consistently act otherwise. Now look at the many, many false claims by Donald Trump, and there you have someone of dubious integrity.

Basically people just do their jobs, and scientists are no different. They very critical of each other if they can find fault, because its in their interests.

"Can anyone really be a scientist and say that 100% of climate change is man-made? "

Obviously yes, if thats what the science finds, and it does or very close to it. It's like certain diseases have very precise causes.

"Climate change has been on-going for the life of the planet and the man-made CO2 emissions simply cannot be 100% unless you have strong evidence that we are in a natural "cooling period". "

There is overwhelming evidence that we are in a natural cooling period. The solar energy output of the sun has been in a decades long cooling phase. Review "Is it the sun" on this website. This is a key reason for scientists beings concerned, quite apart from the evidence and calculations that point at CO2.

"It is not possible that the climate naturally is not going either up or down. "

No because the science doesn't find this. There are over 12,000 research papers on climate change, and many look at this aspect. How many would be enough for you?

"When you say "100%" you sound like an extremist. Most people, and especially conservatives, do not like extremists. Not a smart thing to say."

Maybe so, but when they said 90% that was too extreme as well. Seriously do we have science here, or "pc" correctness on an acceptable level? What is an "acceptable level" and why?

"But back to the Republican position. When they see there are real-life climate scientists like Judith Curry (who I have to admit sounds much more balanced than Michael Mann in testimony before the various Congress committees and who is not subject to any "ad hominem" attacks that seem to be levelled at Christy and Lindzen),"

With respect, you are being one eyed. There's fault on both sides. Michael Mann gets abuse each week for example. Forget the short tempers, and look at the scientific research.

"then the "red team blue team" approach with other scientists (primarily physicists I hope) may be the best answer to the Republicans"

It's a staged, dubious sort of enquiry that can achieve nothing new. It's too small. The IPCC is much, larger and they include sceptics as well as so called warmists, and rotate new scientists on each review panel. You have a very good process, but most people haven't read what really happens overall, only biased little snippets of information taken out of context.

The rest of the world has moved on while the Republicans alone seem stuck. You are just engaging in delaying tactics yet again, and we are sick of it for over a decade now. The rest of the world has seen through the ruse, and moved on to accept the obvious reality of human caused warming.

"Once we get past what Dessler calls "positive statements" (in his very good book on climate change)"

It's a very dubious book, and it's not about books and opinions, it's about the weight of published evidence in proper journals.

"I just think the climate science community has to do a reality check. Trump won and he in all likelihood is here for at least for the remainder of his first term and possibly 8 years (would Pence be any better?). "Anyone who does not accept this is really like the ostrich in the sand pictured on the home page of this website."

That's a real laugh given Trumps approval ratings are so low. I doubt he will even survive this term, and chances of re-election look slim. I'm sorry he is probably a good family man, but imho he is a confidence trickster, and does not have solidly founded policies and beliefs.

"I personally am very unhappy with this situation but the American people have spoken!'

Yeah sure. All your previous comments suggest otherwise.

"Churchill has noted, democracy is close to unworkable but compared to the alternatives, it is the best. "

Well I would agree on that, but not with much else.

Why the Republican Party's climate policy obstruction is indefensible

NorrisM at 16:31 PM on 6 July, 2017

Rightly or wrongly, I think that ClimateGate had a very damaging effect on the climate change views of conservatives everywhere. It is very similar to evidence given by a witness testifying in some legal case who is completely honest in his testimony until the last question, where, in his desire to "win the case" for whatever side, he "fudges" his last answer. The cross-examining lawyer then leads another witness who proves on that very point that the witness was not telling the truth. For any jury, ALL of the evidence of that witness is tainted. I truly think this happened with this issue. Judith Curry has herself admitted that this made her seriously question her position which was until then "mainstream". It is just about irrelevant now as to what was or was not the intention of those emails. The damage has been done. End of story.

When you add this to the issue of the "hiatus" of X number of years whether or not it was really there (the IPCC at least in 2013 coined that term) has added to the legitimate questions of conservatives that are we being led down a garden path. The models did not predict this and therefore are unreliable. That is not an unreasonable position to take IF the hiatus really occurred. For now let us not get into arguments about this because you will NOT convince the Republicans by one "new study" that shows that the IPCC was mistaken.

Then you add on John Christy's famous graph which so impressed Steve Koonin between the predictions of the models and the actual observations (see APS panel hearing below). Do you not think that those pressing the Republicans not to do anything on the climate change file have not read the transcript of the APS panel hearing where three (3) of the top IPCC contributing climate scientists, Collins, Hand and Santer, admitted that the model predictions do not track the observations? Their answer was that they do not trust the observations. Can you not see how this would make conservatives suspicious?

So "97% of climate scientists" does not cut it with Republicans. They simply do not trust the climate scientists believing, rightly or wrongly, that their bread and butter is really based upon making sure that climate change is primarily man-made. Can anyone really be a scientist and say that 100% of climate change is man-made? On that point I fully agree with Perry. Climate change has been on-going for the life of the planet and the man-made CO2 emissions simply cannot be 100% unless you have strong evidence that we are in a natural "cooling period". It is not possible that the climate naturally is not going either up or down. When you say "100%" you sound like an extremist. Most people, and especially conservatives, do not like extremists. Not a smart thing to say.

But back to the Republican position. When they see there are real-life climate scientists like Judith Curry (who I have to admit sounds much more balanced than Michael Mann in testimony before the various Congress committees and who is not subject to any "ad hominem" attacks that seem to be levelled at Christy and Lindzen), then the "red team blue team" approach with other scientists (primarily physicists I hope) may be the best answer to the Republicans. Give it a go and see what happens. If the Koch Bros result happens again, then you will have a very legitimate and strong position to force the Republicans to act. If their own "red team blue team" comes to the conclusion that CO2 emissions are really the cause then we are at least then only into the question of how much warming and decisions as to how best to approach this. So I say, fully support the "red team blue team" even if it has been done before.

Once we get past what Dessler calls "positive statements" (in his very good book on climate change) which are the facts, then we can get into "normative statements" on what we think the results are in economic terms and what we should do about it, both as to mitigation and adaptation.

I do suspect that such a "red team blue team" debate will get bogged down on the facts and largely because we do not have the proper instruments to measure what is happening year to year. If the result is that the Republicans do at least decide to dedicate much more money to funding both weather/climate satellites and water buoys and on-land temperature measurements then it will be a "win" for the majority of climate scientists who believe that we are the cause.

What I found most unsatisfying about the APS panel struck in 2014 to re-evaluate their statement on Climate Change is that after having somewhat of an "appellate hearing" there were no "reasons for judgment", just a decision by the Board of Directors of the APS one year later to effectively stick with their previous statement. I have no problem with them sticking with their same statement but by providing their reasons they could have provided massive "independent evidence" outside the climate science community that man made warming is a major threat to our world. On another post, I have made reference to the APS panel. You can read the APS Workshop Framework Questions and transcript of the proceeding with 6 of the top climatologists on both sides of this debate on the APS.org website just searching "Climate Change Policy Review".

I just think the climate science community has to do a reality check. Trump won and he in all likelihood is here for at least for the remainder of his first term and possibly 8 years (would Pence be any better?). Anyone who does not accept this is really like the ostrich in the sand pictured on the home page of this website.

I personally am very unhappy with this situation but the American people have spoken! Get used to it! As Winston Churchill has noted, democracy is close to unworkable but compared to the alternatives, it is the best. Comey must stay awake at nights realizing how he might have turned the course of history.

What Does Statistically Significant Actually Mean?

Mal Adapted at 01:41 AM on 3 July, 2017

WRT allegations of a statistically-significant 'hiatus', during the interval from about 2000 to about 2014, in the long-term (30+ years) trend of GMST: according to Tamino, because a significant long-term trend had already been shown, the correct null hypothesis isn't that the slope of the GMST trend was zero during the alleged hiatus, but that there was no change in the long-term trend. There wasn't, as it turns out; statistically speaking, no change from either the trend from 1970 - 2000, or the current 30-yr trend, emerges from the noise.

https://tamino.wordpress.com/2016/11/07/testing-for-change/

Temp record is unreliable

JamesMartin at 11:23 AM on 30 June, 2017

The hangup that SkepticalScience.com has in regard to temperature data is that you are exclusively using datasets at least as current as 2015, all of which are tainted by the 2015 adjustments. No wonder you make statements such as

"It is very clear that use of the new data sets make almost no difference to the trend."

If you want to do a fair assessment of the impact that the 2015 corrections had on the historical temperature data, you must dig up those archived datasets recorded before 2015. Otherwise, you just go around in circles claiming that the warming hiatus is over or never was while the corrections "make almost no difference to the trend". Well, if the corrections make no significant difference in the trend, and the current trend is hiatus, then wouldn't we still be in hiatus?

Models are unreliable

MA Rodger at 20:00 PM on 27 June, 2017

NorrisM @1047,

A big long comment from you setting out a lot of stuff. Can I home in on the things you describe as "what also troubles me in everything that I have read so far on climate change." (As you say it is off topic for the thread but...)

(1) The Mediaeval Warm Period. This you describe as being "at least 200 years in at least Greenland and Northern Europe close to or equal to our present temperature." The temperature at the top of Greenland can be reconstructed from ice cores with some accuracy. GISP2, for instance shows results like this graph and some will take the last few thousand years of this graph as proof that recent warming is trivial when compared with previous centuries, as this SkS post describes. Yet the most recent GISP2 data dates from 1855 and when you graft on modern temperature data things look a whole lot different. The idea that Greenland experienced temperatures "close to or equal to our present temperature" is not borne out by the evidence.

2. "During the 1600's and 1700's there was ... skating on the Thames." We do have the CET Central England Temperature record stretching back into the 1600s, temperatures recorded a few dozen miles up the road from the Thames at London. This shows seriously cold winter month have been occuring occasionally throughout the record with the last occuring in 2010. History tells us that Ice Fairs were rare events and they do coincide (almost always) with these exceptional cold CET months. Ice Fairs stopped not because of a Little Ice Age ending or because of global warming but because the old London Bridge was demolished and the banks of the river were embanked. It's all a bit nerdy, but ancient accounts of the Thames freezing continue back in time and continue through the Mediaeval Warm Period (prior to the bridge being built) and are even found for the centuries called by some the Roman Warm Period.

3. You are on much safer ground suggesting that reconciling the temperature record and climate forcing in the first half of the 20th century is not straightforward but very much less safe with the so-called hiatus. There is a lot of comment on these elsewhere within the SkS site. You do raise the idea that if the hiatus was the product of La Nina sucking the warming from the atmosphere and down into the ocean depths. (It is not controversial to state that the years 2007-13 saw lower global temperatures due to La Nina and withut these years the so-called hiatus is truly a non-event.) From this you speculate whether it was potentially the oceans warming the atmosphere 1975-98. You are not the first with such speculation. Bt if there was such a warming from the oceans, there would be evidence of it in the Ocean Heat Content data as it takes a lot of heat to both warm and keep warm the atmosphere. The level of heat required would certainly have to be evident in the OHC data. It is not evident.

Models are unreliable

Eclectic at 18:15 PM on 27 June, 2017

NorrisM @1047 , if I may add some background to Tom Dayton's posts :-

When considering climate models, it is well to remember that the models are based on the physical realities of this world.

And the most basic of relevant points, is that the natural greenhouse effect from CO2 etc. has been "artificially" (anthropogenically) pushed higher by the addition of fossil-origin CO2 to the atmosphere. The result is that the world is warming up — it is gaining heat at the rate of approx. 2 watts per square meter. (Which may not sound very much : yet if you think it through planetwide and decades-long, then it represents a major problem for this planet.) Also, if you think it through (regarding where that heat is going and how it moves about within the system of the planet) then you will realize that a pause or hiatus is simply not possible until such time as the system eventually reaches equilibrium (in 2 or 3 centuries' time).

Therefore if Koonin says there is a real "Hiatus", then he talks nonsense.

If you are a Black-Letter lawyer, you will wish to examine "fake-skeptic" comments without considering their provenance or any ad-hominem aspects. Yet as a pragmatic man-of-the-world lawyer, you will wish to take into account the background information regarding the four protagonists you mentioned [Koonin, Christy, Curry, Lindzen], when you come to assess their evidence.

And you will be aware of human frailties — particularly that frailty called "Motivated Reasoning" : where even very intelligent people (such as Koonin) do bend their rationality and end up deceiving themselves. And doing so, very staunchly! And with apparently honest demeanor!

Climate science is a large area, where you can educate yourself considerably — and if you do so, you will find yourself in agreement with the extensive and almost unanimous consensus of experts (e.g. the U.S. National Academy of Sciences; the U.K. Royal Society; the Vatican's Pontifical Academy of Sciences; and dozens more of peak scientific bodies). All in consensus about Global Warming. Indeed, there is only a score or so of Koonins, Christys, Currys, and Lindzens who hold an outlier position in disagreement with the overwhelming preponderance of scientific experts. And as you yourself gain education in climate science, you will understand that these 4 protagonists, despite their intelligence, have all managed to make a very poor judgment of the actual position. And that, as you look beyond their rhetoric, you will find that their apparently scientific arguments are empty and false.

How is it possible for 4 intelligent people to be so very wrong? It is because their emotions have pushed them into motivated reasoning. Motivated reasoning by Koonin / fundamentalist religious bias from Christy and Lindzen / and something less clear, from Curry [about whom you need ask: Cui Bono ].

In the strictest sense, these four are not being scientists — because they have allowed their emotions to override their dispassionate intellects.

They have muddied the waters and confused your understanding of the significance of models (and of the physical realities).

Models are unreliable

NorrisM at 08:59 AM on 27 June, 2017

I would first like to state that I have finally found a website that is balanced on this very emotional issue. I also want to thank SemiChemE and Tom Curtis (along with a few others) who have engaged in a very fascinating discussion on climate models.

My intention is to pose a question on climate models in keeping with this blog, however because this is my first post, I would like to explain my background. I am a lawyer by training and have a very limited base in physics (took Latin in Grade 12 rather than physics) although I always did well in science. I will also disclose that I do have an involvement in the Canadian oil and gas industry notwithstanding that I live in Vancouver, BC.

Ever since the issue of global warming came to the fore in the late 1990’s and since, I have to admit that I have tended to accept the “scientific consensus” if only because I had no reason to question it. Climategate shook my confidence in 2009 but if Neil DeGrasse Tyson still believes that the principal causes are anthropogenic then far be it for me to question it. However, it always seemed logical to me that a first step in reducing the effects of CO2 should be to move from oil and coal to natural gas (especially for electrical generation) which puts about one half of the pollutants into the air compared to coal and oil. After spending enough holidays in France, I have also thought that a switch to nuclear energy made more sense than disfiguring our planet with massive wind turbines and great areas of solar panels. Driving from LA to Palm Springs is not a pretty sight. But I do appreciate that there are real concerns relating to disposing of nuclear waste and issues of terrorists getting their hands on nuclear fuel. However, someone as significant as James Hansen believes that we will not achieve our goals without a turn to nuclear energy.

In any event, my recent interest in the causes of global warming really came about because I have two sisters who are just about no longer on speaking terms owing to their disagreements on global warming. When one sister called me asking where I stood on climate change and if I truly believed that this was all a “global conspiracy of the left” to increase taxes and government control over our lives, I promised her that I would buy some books on both sides of the argument and get back to her. Needless to say, I do not believe in conspiracy theories of any sort.

So the two books I located were The Science & Politics of Global Climate Change by Dessler and Parson and Climate Change the Facts edited by Alan Moran.

By the time I was finished with Dessler’s book I was convinced of the science. Then I read the essays in the Moran book and found myself at least questioning some things.

I actually then went back and re-read Dessler’s book to see where the gaps were. I have to say that when I found that Mark Steyn had an essay in the Moran book I almost did not read the book because of his extreme views. Just to make my political views clear, I think Donald Trump poses a major threat to liberal democracy in the US and to the world in many ways. But it does look like the US institutions may be able to withstand him and his cohorts. I also follow Sam Harris’s podcasts “religiously”.

Since reading these two books I have largely pursued my research on the web even reading the submissions of the four climatologists on March 25, 2017 to the House Committee on Science Space and Technology.

Based upon Judith Curry’s reference in her submission, this led me to the most fascinating discussion of the topic of climate models by a panel of physicists formed by the American Physical Society (APS) which posed questions to six (6) well-known climatologists having “different perspectives”. Three (3) of them (Collins, Santer and Held) are IPCC climatologists and the other three (3), Curry, Christy and Lindzen are on the other side of the debate. This was the 2014 Workshop sponsored by the APS as part of its 5 year review of its Climate Change Policy Statement.

As a lawyer, I have to admit that if I treated (i) the IPCC 2013 Assessment as an appellate lawyer’s factum, (ii) the Workshop Framework posed as questions from the bench, and (iii) the 600 page transcript of the panel hearing as the “give and take” between the judges and lawyers during the oral argument of the appeal, I would have predicted a “win” for Curry, Lindzen and Christy and a “loss” for Collins, Santer and Held. Both the Workshop Framework questions and the transcript are on the APS.org website. Just search “Climate Change Statement Review”. If anyone has read any legal transcript of a hearing you know it is a simple read so don’t be put off by the “600 pages”.

The APS panel consisted of six (6) arm’s length physicists (with no axe to grind) chaired by Steve Koonin who were asking hard questions of both sides. What actually struck me as very astounding was how honest Koonin was about his previous lack of understanding as to how uncertain climate science is owing to the uncertainties underlying the climate models.

This panel hearing took place in February 2014. By November 2015, the judgment of the Board of Directors of the APS was in. The connection between increases in CO2 and global warming was “compelling”. However, the APS did acknowledge that there were significant uncertainties in the science and urged sustained research in climate science.

Where my comparison with an appellate hearing breaks down is that no appellate court would render a significant judgment without providing its reasons. We do not get any reasons from the panel as to why it recommended to the Board of Directors (as I assume it did) that the APS “stay the course” with its policy statement notwithstanding the serious reservations you could see in Koonin’s and other panel members questions to Collins, Santer and Held and the weak answers provided by them. The IPCC climatologists in effect admitted that Christy’s now famous chart showing how far apart the average predictions of the climate models were from actual observations was “old information” and did in fact represent the existing state of models predictions versus observations. See Santer page 504. The IPCC climatologists effectively said that they could not trust the observations! Koonin’s rhetorical question to Held to this "observational" response earlier was: “So the ability then to reproduce historical data is neither necessary or sufficient to predict the future. Is that what I understand?” See page 453 of the transcript. Held effectively avoids answering the question. See page 454. Read it yourself and see if you disagree with my view of his response.

So here is my question.

From everything that I have read so far, other things being equal, a doubling of CO2 in the atmosphere from pre-industrial levels of CO2 of around 280 ppm to 560 ppm will increase the global surface temperature by about 1 to 1.2C and the balance of the predicted range of 1.5C to 4.5C of the IPCC 2013 Assessment is based upon “positive feedbacks” resulting from increased water vapour that is assumed will form arising out of the 1C increase by CO2. I accept (or understand) that the 1C increase is “solid physics” or “hard science”.

Is it “solid physics” that:

1. Water vapour will in fact increase as modelled?
2. Water vapour will cause the predicted additional increase in temperature by a factor of 2 to 3 times?

Although this next observation is not specifically focused on the climate models, what also troubles me in everything that I have read so far on climate change is the following:

1. The Mediaeval Warming Period had temperatures for at least 200 years in at least Greenland and Northern Europe close to or equal to our present temperature.

2. During the 1600's and 1700's there was a "Mini-Ice Age" when they were skating on the Thames. We were just coming out of this cold period at the beginning of the American Revolution (good timing).

3. From 1990 to 1940 we experienced about .3C warming; then from 1940 to 1975 there was a levelling off or cooling period; then from 1975 to 1998 we experienced .5C warming; and then there was a levelling off (termed the “hiatus” by the IPCC) of now about 17 plus years that may or may not have ended in 2015 (El Nino event 2015-2016). I appreciate that 1998 was an El Nino year but the IPCC 2013 Assessment recognized the “hiatus” up to that time.

If climatologists cannot explain why these other warming and cooling periods occurred which, other than the 1975-1998 period, were primarily or completely caused by natural climate change, then why can they so confidently claim that this one warming period was primarily caused by the CO2 rise? Just because there was a concomitant rise in CO2? What about the rise of CO2 from 1950 to 1975?

The models predicted that our temperature would increase on a linear basis. There were no “waves” in the models. I guess based upon Michael Mann’s most recent testimony the most recent peer reviewed papers are now suggesting that we will be going up in steps or waves. Can we now expect that the new models with show the steps or waves?

So where did the “warming” go during this “hiatus”? If the answer is into the oceans, then why did the “warming” not come from the oceans during the period 1975-1998? Could we have had a cooling period during the “hiatus” that offset the warming from CO2 during this period? What are the impacts of a decrease or increase in low clouds caused by natural factors which impacts the amount of sunlight hitting the earth? Because of computer capacity issues, we can only make “parameterizations” of clouds in the models. These are the kinds of questions that make me question the validity of the models.

When we talk of the difference between weather and climate we say we cannot predict weather but we can predict climate because we know that next July it will be warm. But why do we know that? Not from models, from observation. If observations and models do not correspond, when do we admit that the models do not have sufficient predictive value to be relied upon? It is OK for science to say “we just do not presently understand the science sufficiently to make reasonably accurate predictions”.

On the other hand, here are the major science societies of the world like the APS, the US National Academy of Sciences and the UK Royal Society coming out strongly in support of the proposition that man-made global warming is a serious problem and is going to get worse. My worry is that they got on a band wagon in the early 2000’s before the “hiatus” was apparent and they now find it very difficult to get off even when they see that these models are not predictive.

I apologize for such a long-winded initial blog. If you think I have to reduce it, please advise.

SkS Analogy 7 - Christmas Dinner and the Faux Pause

HK at 23:55 PM on 10 June, 2017

If you want to make the point that short-term noise doesn’t negate the long-term climate trend, maybe the best analogy is daily temperatures vs. the seasons. Just as manmade GHGs now are the main global climate forcing on a decadal to century time scale, the shifting distribution of insolation is the main seasonal forcing. Clearly that doesn’t mean that every day during the spring is warmer than the previous one – a few colder days doesn’t mean that the coming summer is cancelled.

To test this pretty obvious concept, I checked the average daily temperatures at my local weather station here in south-eastern Norway from March 1 to May 31 this year. It turned out that of these 92 successive days, only 45 were warmer than the previous one while 45 were colder and 2 the same, and there was nearly no warming the first three weeks of April. The long "hiatus" in April didn’t prevent the overall temperature to rise about 15^oC from early March to late May.

This shows that as long as the underlying forcing keeps on increasing, the warming will continue despite some ups and downs that are mostly caused by redistribution of heat within the climate system.

Temp record is unreliable

blackhole at 11:11 AM on 4 June, 2017

I reviewed with interest the comments made to cosmoswarrior et. al. in comments 405-414. Tom Curtis points out in comment 406 that there is almost no difference between the raw and adjusted data from 1980-present for GNCNv3 data. Examining your plot, I would have to say I fully agree. Similarly, you showed plots of the new corrections, old corrections, and uncorrected NOAA temperature dataset in the figures in comment 409. Again, I would have to agree there is not much difference between three from about 1940 forward.

There is one statement you made, however, that needs correction. This is in comment 413(2) where you state:

Heller's giff does not demonstrate any significant change in values. Rather, it exhibits a change in the range of the y-axis from -0.6 to 0.8 for "NASA 2001" to approximately -0.85 to 1 for "NASA 2015". That represents a 32% increase and accounts for nearly all of the apparent change in trend - particlularly post 1980.

I downloaded this animated .gif file myself and extracted the individual images for 2001 and 2015. I then compared scales by copying and pasting the two axises from the 2015 image onto the 2001 image, and then sliding each axis from the 2015 image next to the corresponding axis of the 2001 image. It turned out that the horizontal axises of the two images were identical and the scale of the vertical 2015 image was slightly smaller than that of the 2001 image. Therefore, the actual slopes of the data plot for 2015 are slightly higher than what they appear in the plot image. I would have shown this image, but I am not sure how to do it just yet. While this data is not important for the points I want to make and carries no credibility with you, I thought I should point out the error since the topic came up recently.

From what you have pointed out in your most recent comments, it seems that you have debunked the myth about NOAA eliminating the "warming hiatus" in its paper of 2015. What happened was that we had a warming trend from about 1980 until 1998 when the warming rates were greatly reduced. We then continued on that level trend until 2015 when NOAA announced that they had shown with their "corrected" data that the warming hiatus never existed. Contrary to NOAA's claims, however, you pointed out that the corrected and uncorrected data are very nearly identical and therefore could not have eliminated the hiatus. This means, of course, that the hiatus not only existed back in 1998 but continues to this day.

So thanks for your inputs, Tom Curtis. You have been most helpful to us "climate contrarians" in making our case.

Temp record is unreliable

Tom Curtis at 21:26 PM on 31 May, 2017

landdownunder @413:

1) Tony Heller (aka Steven Goddard), producer of the www.realclimatescience.com website is not a climate scientist, former or otherwise. His qualifications are a Bachelors degree in Geology, and a Masters in Electrical Engineering. So far as I can determine, he has never published a peer reviewed paper of any description. He is well known as a serial misreprenter of data, a prime example of which is the gif which he produced, and you show.

2) Heller's giff does not demonstrate any significant change in values. Rather, it exhibits a change in the range of the y-axis from -0.6 to 0.8 for "NASA 2001" to approximately -0.85 to 1 for "NASA 2015". That represents a 32% increase and accounts for nearly all of the apparent change in trend - particlularly post 1980. An honest presentation of the data would have plotted both on the same axis, and ideally on one graph to allow direct comparison, like this:

(Source)

As can easily be seen, the temperature trend between 1980 and 2000 is nearly the same in all versions, and has certainly not doubled. In fact, the GIFF is doubling misleading. The 1998, 2000, 2012 and 2016 versions of the NASA GISS Meteorological Stations only temperature index are downloadable here (as also for the Land Ocean Temperature Index). the 1979-1998 trends are, respectively 0.184, 0.134, 0.169 and 0.177 ^oC/decade. You will notice that largest change is the 27.2% reduction in the trend from the 1998 to the 2000 version, followed by the 26.1% increase from 2000 to 2012.

Clearly the history of changes is not one sided, indicating the scientists concerned are following the data. Equally obvious is that Tony Heller has cherry picked an interval to show a rise in trend, even though the available history of adjustments results in a net reduction in the trend of the last two decades of the 20th century, not an increase.

Returning to cosmoswarrior's specific claim, a 32.1% increase in the trend (2000-2016) is not a doubling of the trend. Not even close, so even on your generous interpretation, that remains a gross error.

3) Unlike the AGW "skeptics", who focus on the facts of the changes without regard to the reasons, actual climate scientists focus on the reasons, which they detail in peer reviewed publications, and in the case of GISS, on site as well (see prior link). One main contributor to the change in trend from for the meteorological stations index has been the increase in the number of stations. The first version of GISS (1981) relied on just 1000 stations. That increased to 2200 in 1987, and to 7200 in 1999 (between the 1998 and 2000 versions). In 2005, a small number of stations in Antarctica were introduced, which was not a major increase in number, but very significant in improved coverage. Finally, in 2016 the number of stations jumped to 26000.

There have also been significant improvements in techniques, as detailed by GISS:

"We have gone through the archives to show exactly how these estimates have changed over time and why. Since 1981 the following aspects of the temperature analysis have changed:

The simple procedure used in 1981 was refined as documented in Hansen and Lebedeff (1987), using 8000 grid boxes to allow mapping and analysis of regional patterns.

Surface air temperature anomalies above the ocean were estimated using sea surface temperatures from ships and buoys starting in 1995 as documented in Hansen et al. (1996).

Starting in the 1990s, the methodology took into account documented non-climatic biases in the raw data (e.g. station moves) and eliminated or corrected unrealistic outliers (Hansen et al., 1999).

Areas with missing data were filled in — using means over large zonal bands — rather than restricting the averaging to areas with a defined temperature change (Hansen et al., 1999).

A method was devised in 1998 and refined in 2000 to adjust urban time series to match the long term mean trend of the surrounding rural stations, Hansen et al. (1999, 2001). This adjustment uses the full data series to make the best estimate of the rural/urban difference and so can change as the time-series are extended (and more data comparisons are available). Starting in 2010 night-light radiance rather than population data were used to classify stations (Hansen et al., 2010).

Usage of water temperatures as proxy for air temperatures was more accurately restricted to areas without sea ice starting in April 2006."

The merits of these changes in method can be argued, although they all seem like eminently reasonable improvements to me. But if you object to them, you have to make that argument. You cannot simply say that you do not like the result and therefore the methods are wrong - still less that they are fraudulent. The later, however, is the method employed charlatans like Tony Heller.

4) The involvement of politicians in challenging the adjustments is in no way evidence of the scientific invalidity or otherwise of the adjustments. It is evidence of where politicians think they can get political milage, either with there base or with their donors. Curiously, the second largest category of donors of Lamar Smith, who led the congressional inquisition on Karl et al, was from the Oil and Gas industry. Lamar Smith is not alone. In 2016, the Oil and Gas industry made political donations to the tune of $103 million dollars, 88% of which went to Republicans.

5) Finally, you quote Zeke Hausfather as saying:

"... they increased the amounts of warming that we have experienced pretty significantly. They roughly doubled the temperature trend since 1998 compared to the old versions of the datasets"

and go on to suggest, "...is also consistent with cosmoswarrior's statement". However, cosmoswarrior's statement was explicitly about the last two decades of the 20th century (1981-2000), not the interval from 1998-2012 that Zeke Hausfather was talking about. His comment was, therefore, entirely irrelevant to cosmoswarrior's eggregiously false claim. More importantly, the 1998-2012 trend "roughly doubled" not because there was a large increase in the trend, but because the trend was low. The change in trend over that period was from 0.039 C per decade to 0.86 C/decade, a change of approximately half (63.5%) of one standard deviation of the error of the new trend as determined on the SKS trend calculator.

Following the logic of the advocates of the existence of a "hiatus", that is no change at all.

Temp record is unreliable

Tom Curtis at 15:47 PM on 29 May, 2017

While strongly suspecting that moonrabbit @411 is yet another sock puppet, I will point out that my post at @406 exclusively criticizes cosmoswarrior/diehard/dieharder's claim @405 that:

"Not only that, but the temperature history during the last two decades of the 20th century was rewritten to double the rate of temperature increase."

As can be easilly seen from the graph @406, and the equivalent graph from Karl et al shown at @409 (panel b), the trend in the last two decades of the twentieth century, ie, from 1980 onwards, was not doubled when comparing adjusted to raw data. cosmoswarrior/diehard/dieharder's claim to the contrary is indeed a gross error. Somebody who cannot acknowledge even that, and who continuously misrepresents the argument made against his claim to avoid doing so in not amenable to reason.

If they (and moonrabbit, on the assumption that is not just another sock puppet) cannot acknowledge even that gross error, or even correctly represent the argument against it, how on earth can they be expected to discuss reseanably the more subtle issues relating to the 1998-2012 trend (ie, the so called "hiatus").

Temp record is unreliable

moonrabbit at 15:21 PM on 29 May, 2017

I would like to comment on your responses to cosmoswarrior and diehard in their postings about the reliability of NOAA temperature data. First, in the response Tom Curtis gave to cosmoswarrior in @406, he showed the GHCNv3 data before and after the corrections, and pointed out that there was "almost no difference between the raw and adjusted data from 1980 forward". Tom Curtis then used this fact to argue that cosmoswarrior was incorrect in his/her statement about the data adjustments made in 2015 (which eliminated the "warming hiatus") also rewrote the temperature data for the last two decades of the 20th century. This is not an equitable comparison, however, since GHCNv3 was a land-based dataset only and the major changes had to do with the sea-surface measurements. Therefore, we cannot use this fact to argue that the statement by cosmoswarrior about "pause-buster" data corrections is "simply false" or that he/she is in "gross error".

At this point, I don't believe the fact can be disputed that NOAA made major changes in temperature data in June 2015 which in fact eliminated the appearance of a warming slowdown after 1998. The writings and videos by Kevin Cowtan and Zeke Hausfather that you in fact post and reference discuss the affects of these "adjustments" on the temperature trends. Additionally, news of these sweeping changes, including rewriting of data (which at least most of us have never seen before in any scientific effort), caused a huge controversy in the entire climate science field and eventually prompted a Congressional investigation. Therefore, if cosmoswarrior and diehard are mistaken in their statements, they are far from being the only ones.

Temp record is unreliable

dieharder at 13:24 PM on 23 May, 2017

No, Tom Curtis. Your graphs do not satisfy my "quibbles" — not in the slightest. What I am looking for are the "corrections" that were applied to the original data (which clearly showed a warming hiatus) in order to eliminate the warming hiatus. These data adjustments, as I stated in a previous posting, totally eliminated the warming pause and about doubled the warming rate. Now, before negating me again on this claim and being too quick to delete this posting, be advised that this was part of the introductory statement made by Zeke Hausfather on the video Recent Ocean Warming has been Underestimated. In his words, "... they increased the amounts of warming that we have experienced pretty significantly. They roughly doubled the temperature trend since 1998 compared to the old versions of the datasets." So who am I supposed to believe, you or him!?

Now from the email newsletters I get from the "denier" community along with a few online news articles about whistleblowers and NASA and NOAA fighting the Congressional investigation, I believe I have some insight as to why you can't come up with the dataset showing the adjustments that did away with the warming hiatus. NOAA simply refused to cooperate with the investigation and witheld the subpeonad email communications and scientific data. Since this was still during the Obama administration, the Whitehouse would not enforce their compliance. Therefore, the world may never know just what killed the hiatus at NOAA, and I'm supposed to accept their "data" as "overwhelming evidence with 97% consensus". — Give me a break! If this is your version of science, you can keep it!

Finally, I would like an apology from you for your statement "Rather than admit that gross error, he quibbles about the data source, and about the change in the NOAA temperature data set detailed in Karl et al (2015)." We know now that my claim was not erroneous at all. Either that or Zeke Hausfather made the same "gross error". Also, I resent your use of the term "quibbles" as it gives readers the impression that my concerns are over trivia as opposed to the primary issue of assessing the amount of global warming we are experiencing.

Temp record is unreliable

Tom Curtis at 12:51 PM on 22 May, 2017

cosmoswarrior/coolearth/diehard appears to not like my pointing out @406 the gross error in his claim that "...the temperature history during the last two decades of the 20th century was rewritten to double the rate of temperature increase". Rather than admit that gross error, he quibbles about the data source, and about the change in the NOAA temperature data set detailed in Karl et al (2015). To deal with his quibbles, here is a comparison of raw and adjusted data in the new data set in figure 2 of Rove et al (2015):

The top panel shows the difference between prior adjusted data set, and the new adjusted data set. It is very clear that use of the new data sets make almost no difference to the trend. In the bottom panel is a comparison of the new adjusted data set to the raw data set. Post 1945 there is almost no difference, and in particular it is clear that claims that "...the temperature history during the last two decades of the 20th century was rewritten to double the rate of temperature increase" are at best massively misinformed, and at its source, a lie.

With regard to the disappearing of the "hiatus", that comes about in Karl et al (2015) not because they use a new method of adjustments, but because they use two new data sets. Specifically, they switch from ERSSTv3 to ERSSTv4 for marine temperatures, and from GHCNv3 to the ISTI database for land temperatures. The later represents a switch to a larger database with a more extensive coverage. It represents more data. The change in ERSST versions involves, "...updated and substantially more complete input data from the International Comprehensive Ocean–Atmosphere Data Set (ICOADS) release 2.5; revised empirical orthogonal teleconnections (EOTs) and EOT acceptance criterion; updated sea surface temperature (SST) quality control procedures; revised SST anomaly (SSTA) evaluation methods;
updated bias adjustments of ship SSTs using the Hadley Centre Nighttime Marine Air Temperature dataset version 2 (HadNMAT2); and buoy SST bias adjustment not previously made in v3b." It's effect on the NOAA temperature record is discussed in detail by Kevin Cowtan here. It has also been discussed by Zeke Hausfather as part of a more comprehensive discussion of the NOAA updates.

Finally, the "hiatus" is not defined as a period of zero or negative trend in Global Means Surface Temperature (GMST). Rather, it is defined as a period in which the zero trend is within the error margin of the observed trend. As it happens, the long term trend has been within the error margin of the observed trend through out all periods considered to be part of the hiatus. That means, logically, there is no more reason to consider the trend to be zero than there is to consider it to have continued unabated. Indeed, given that all purported periods of the "hiatus" are parts of periods in which there is a statistically significant positive trend, there is more reason in those periods to consider them to be periods or warming rather than stasis. In short, the "hiatus" was at best only a statistical artifact such that a small change in the observed trend (approximately one standard error) over the period of the "hiatus" makes it transparently an artifact. That so small a change can make it "disappear" shows it to have been, at best, an artifact all along.

Temp record is unreliable

diehard at 04:18 AM on 21 May, 2017

So where is all of this temperature data that shows the "hiatus" isn't real? It's obviously not the GHCN data shown in Comment 406. As Tom Curtis himself points out "there is almost no difference between the raw and adjusted data from 1980 forward". So where is this data with a big enough difference between the raw and adjusted values such that the raw data shows a warming hiatus but the adjusted values do not?

Now, before you delete this question/comment and disable my login, I believe I am asking a simple, straight-forward question that should be easily answerable if in fact the adjusted data is what the elimination of the warming hiatus is based upon. Therefore, if this comment is simply deleted before I receive a satisfactory answer to my question, I will proceed on the basis that no such data exists, and that eliminating the hiatus was based on politics and not science.

Temp record is unreliable

HK at 22:10 PM on 20 May, 2017

NOAAs conclusions about the non-existing "hiatus" have been confirmed by other studies using independent data. Zeke Hausfather from Berkeley Earth explains how they did it here and here.

BTW, the Berkeley Earth surface temperature project was founded by physicist and former climate skeptic Richard Muller to address the most important objections the deniers had to the "official" temperature records. They constructed their own temperature record, which turned out to be very similar to the ones from NOAA, NASA and the British HadCRUT4.

Temp record is unreliable

cosmoswarrior at 19:52 PM on 17 May, 2017

How can it be said that the temperature record is reliable when in June 2015, NOAA published a paper describing certain adjustments they had made to "improve" the data, and in so doing, they eliminated the 17 year warming hiatus that was troubling many climate scientists. Not only that, but the temperature history during the last two decades of the 20th century was rewritten to double the rate of temperature increase. Assuming those adjustments were necessary to correct data errors, it opens questions as to the competency of the individuals involved in the data handling. Evidently, there were serious problems in the data gathering and processing that went on for 20-30 years, and it took an apparent slowdown in the warming to bring it to anyone's attention. Allegedly, the problem is "fixed" now, but with the lack of competency that plagued the data handling process, how do we know the fix is any better than the original?

2017 SkS Weekly Climate Change & Global Warming Digest #19

chriskoz at 13:11 PM on 15 May, 2017

nigelj@1,

The technique you're probably asking for, to determine and quanify the so called recent "slowdown" in AGW temp signal is called "change-point analysis", which does piece-wise linear function fitting to the data in order to get the optimal linear model. You obviously have to demonstrate that changes in your model be statistically significant to avoid overfitting.

Stefan from RC has done it as described here and concluded there was no statistically signifficant change in temp signal derivative since ~1970, putting to bed any serious claims of "slowdown" or "hiatus". Also, Tamino nicely explained the statistics behind this method here.Note that Stefan's article comes from Dec 2014, which is before latest monster ElNino pushed surface temps higher. Tamino's blog comes from Apr 2015: so when ElNino in question just started.

Of course, science deniers' claims have nothing to do with reality or statistical methods, so they'll continue to bang their silly "it's stopped warming..." talk no matter what.

NY Times hired a hippie puncher to give climate obstructionists cover

Charles S at 08:07 AM on 3 May, 2017

nigelj: I think you are mistaken about interpreting the spike in the last 3 years as an increase in rate. Just as the 'hiatus' didn't tell us anything meaningful, there is as yet no sign that the last 3 years are anything other than an El Niño driven spike (indeed, the paper referenced in "Climate keeps on keeping on", (Rahmstorf, 2017) a few posts before this one, demonstrates that).

The increase in rate is inferred (and predicted) from the more than geometric increase in CO2 production predicted in RCP8.5, as discussed in the Skeptical Science article I linked to. A steady rate of doubling of CO2 drives a linear temperature increase, but if the time between CO2 doubling decreases over time, then the temperature increase will be more than linear.

joe: I think you are mistaking the amount of warming over the last century, which NASA lists, with the current estimated linear rate of warming per century. Cahill et al, 2015 confirmed that the rate of global warming changed in ~1970 (as is obvious from just looking at any plot of global average temperature over the last 135 years), so the rate from 1970 onward is the relavent rate, not the rate from 1916- 2016. Under RCP8.5, we aren't going back to the rates from 1916-1970 any time soon. That 1970-present rate is ~1.7C/century.

Models are unreliable

SemiChemE at 12:27 PM on 23 March, 2017

Here are a few references, discussing the importance of Ocean-effects on global Climate Sensitivity.

Balmaseda, Magdalena A., Kevin E. Trenberth, and Erland Källén. "Distinctive climate signals in reanalysis of global ocean heat content." Geophysical Research Letters 40.9 (2013): 1754-1759.

Meehl, Gerald A., et al. "Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods." Nature Climate Change 1.7 (2011): 360-364.

Raper, Sarah CB, Jonathan M. Gregory, and Ronald J. Stouffer. "The role of climate sensitivity and ocean heat uptake on AOGCM transient temperature response." Journal of Climate 15.1 (2002): 124-130.

There are many, many more such papers. Clearly, the oceans are very important to climate Sensitivity.

As for the evolution of Ocean Currents over time, here's a nice summary:

https://earth.usc.edu/~stott/Catalina/Oceans.html

As you can see, prior to ~30 million years ago, the arrangement of the continents was different, which had a dramatic impact on ocean circulation patterns. The Atlantic Ocean was much smaller and the isthmus of Panama had not formed. Given that Atmospheric-Ocean coupling is a major factor in determining climate sensitivity (see references above) and that due to geological changes in the configuration of the continents the Ocean circulation patterns were different, it is entirely reasonable to believe that climate sensitivities prior to 30 million years ago may have been different from those today. Thus, as I stated before, I would be very skeptical of the relevancy of paleoclimate data from >30 million years ago for predicting the modern climate.

Whistleblower: ‘I knew people would misuse this.’ They did - to attack climate science

citizenschallenge at 23:58 PM on 9 March, 2017

Speaking of communicating clearly - what responsiblity do scientists have in that regard? Specifically I've spent a lot of time looking at Fyfe 2016 and it is about a poorly and counter-productively written as I can imagine - but better not call them on it. All ya get is hurt feelings and slammed doors, no matter how carefully or constructively one constructs their arguments.

Fyfe et al. 2016: stamp collecting vs informing and clarifying. Examining a failure to communicate
... and a question of perspective.
Alternately, Behold Seepage in Action.

(Skipping my introduction here)

Fyfe 2016 introduction:
It has been claimed that the early-2000s global warming (b) slowdown or hiatus (a)(e), characterized by a reduced rate of global surface warming (c), has been overstated, lacks sound scientific basis, or is unsupported by observations. The evidence presented here contradicts these claims (d).
_______________________________________________________

The problem >>>

Why the labyrinthian phrasing? Simplify wording. Clarify meaning.

(a) Creates a false equivalence between “slowdown” and “hiatus” - hiatus means STOPPED! But, Global Warming never stopped!

(b) Creates a false equivalence between “global warming” and “global mean surface warming.”

(c) Furthermore: “early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming” - implies “surface” warming slowdown (or faux hiatus) is a symptom of a “global” warming slowdown.

(d) “Evidence presented here contradicts these claims.” Given the paragraph's convoluted wording one could easily conclude this is saying: the “hiatus” (that is global warming stopping) is not contradicted

… which is exactly what the contrarian PR machine was hoping they could twist any science into. Why make it so easy?

(e) Why even use the politically charged term “hiatus” beyond a footnote? What possible purpose does it serve other than to fatally wound clarity and invite gross misinterpretation?

This paper seems a textbook example of “seepage” in action. Or as I would phrase it, unconsciously adapting the contrarian’s script. Please keep this in mind as you continue.
_______________________________________________________________________
Fyfe: ¶1 A large body of scientific evidence — amassed before and since the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5)1 — indicates that the so-called surface warming slowdown, also sometimes referred to in the literature as the hiatus,
__________________________________________________________
“sometimes referred to...” ? What purpose is there in reinforcing the faux “hiatus” meme?
_______________________________________________________________________
Fyfe: was due to the combined effects of internal decadal variability and natural forcing (volcanic and solar) superimposed on human-caused warming2.
__________________________________________________________

“internal decadal variabilities” - that would be heat transport?

Why not get explicit and point out that Atmospheric Physics are what's causing Global Warming - not Heat Transport between the oceans and the surface?
_______________________________________________________________________

But that's just the beginning highlights. For the entire exercise in futility visit: http://whatsupwiththatwatts.blogspot.com/2017/03/fyfe2016-stampcollecting-vs-informing.html

Dear Mr President: another message from across the Pond

One Planet Only Forever at 15:31 PM on 1 March, 2017

I like the Death Spiral presentation of the Arctic Sea Ice Mass.

It may be even more effective paired with a regular line graph. The line graph would show how the rate of reduction has noticeably increased since the late 1990s (no statistical evaluation required). The spiral makes it difficult to see that there was only a slight reduction from 1978 to the late 1990s (the first 20 years) compared to the more recent rate of reduction (the most recent 20 years).

The implication is that although the rate of atmospheric CO2 increase has been generally steady some of the impacts on significant aspects of the global climate system are accelerating, even through the period of time that some people still try to claim was a hiatus or stop of the warming of the surface.

Global warming hiatus claims prebunked in 1980s and 1990s

Haze at 21:01 PM on 6 February, 2017

The claims by Dr John Bates, a climate scientist (it seems actually a meteorologist) formerly responsible for NOAA’s climate archive, (https://judithcurry.com/2017/02/04/climate-scientists-versus-climate-data/) do bring a sense of unease about this discussion on "the pause". Dr Bates says this: "The most serious example of a climate scientist not archiving or documenting a critical climate dataset was the study of Tom Karl et al. 2015 (hereafter referred to as the Karl study or K15), purporting to show no ‘hiatus’ in global warming in the 2000s The most serious example of a climate scientist not archiving or documenting a critical climate dataset was the study of Tom Karl et al. 2015 (hereafter referred to as the Karl study or K15), purporting to show no ‘hiatus’ in global warming in the 2000s" Dr Bates goes on to say:

"I questioned another co-author about why they choose to use a 90% confidence threshold for evaluating the statistical significance of surface temperature trends, instead of the standard for significance of 95% — he also expressed reluctance and did not defend the decision. A NOAA NCEI supervisor remarked how it was eye-opening to watch Karl work the co-authors, mostly subtly but sometimes not, pushing choices to emphasize warming. Gradually, in the months after K15 came out, the evidence kept mounting that Tom Karl constantly had his ‘thumb on the scale’—in the documentation, scientific choices, and release of datasets—in an effort to discredit the notion of a global warming hiatus and rush to time the publication of the paper to influence national and international deliberations on climate policy."

Are these comments valid? They seem to be and if so do lead to questions about the veracity of some authors.

More than 100 comments found. Only the most recent 100 have been displayed.

Climate Science Glossary

Term Lookup

Settings

Term Lookup

Settings

Latest Posts

Comment Search Results