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Tom Dayton at 00:22 AM on 26 January 2016Wigley and Santer Find the IPCC is too Conservative on AGW
Jsalch, basic physics was used to project human-caused warming many decades before it was possible to observe it. See the post How Do We Know More CO2 Is Causing Warming? Also read The History of Climate Science, and for details Spencer Weart's The Discovery of Global Warming. Watch Pierrehumbert's AGU lecture describing successful predictions, or at least read a summary of his talk. And Climate Change Cluedo.
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Jsalch at 23:07 PM on 25 January 2016Wigley and Santer Find the IPCC is too Conservative on AGW
It appears that the whole point of causality versus correlation is skipped. I am a statistician, not a physicist or chemist. However, most of these types of paper seem to read ... "if [assumptions from climatology models], then humans are the problem."
I'd like to see where causality is addressed.
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Forrest at 21:22 PM on 25 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
Cruz is trained as a lawyer - his job is to advocate for his client, without regard for the truth. If he gets a murderer acquitted, he has done his job regardless of whether the suspect was actually guilty or not. Sometimes lawyers don't do well in a field like science, where the goal is to find out the truth, regardless of any potential impacts it may have.
I find it amusing when deniers insist that the raw data are more accurate than the corrected data, while also insisting that raw data are inaccurate and must be adjusted for urban heat island effect, poor station siting, and other factors that might conceivably raise the temperature.
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Eclectic at 17:56 PM on 25 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
Scaddenp @ 9 , please . . . do tell the dreadful secret of your cognitive bias ~ unless it involves something actually illegal, of course !
No, I don't think we can excuz Cruz, on the grounds that no-one else is absolutely perfect. There are shades of grey in many concepts, to be sure . . . and especially on the spectrum between undoubted sanity and undoubted insanity. Slightly off-white and almost pitch-black, may well be on the same spectrum ~ but there is a huge qualitative difference, that amounts to a recognizable difference of category.
Digby's possibility (1) is something that features on a dimension at right angles to the sane/insane spectrum. And that is: the moral dimension. There we are treading more on the territory of religion & ethics.
But you could equally argue that "cognitive bias" [ possibility No. 2 ] also has a moral dimension of good/evil, when the bias is extreme.
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scaddenp at 12:40 PM on 25 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
(2) is simply cognitive bias and frankly I think everyone suffers from it to a certain degree (I do). Fortunately, the scientific method as it has evolved, and when practised as a community gives us a way to break from the biases. Getting someone to accept a proposition that is conflict with their values and/or identity is close to mission impossible.
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Digby Scorgie at 12:23 PM on 25 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
Glenn
Is Cruz declining to tell all of the truth or is he just denying the truth?
There are two possibilities:
(1) Cruz knows that global warming is a threat.
(2) Cruz does not want to know that global warming is a threat.
What do you call someone of the first type — psychopath?
What do you call someone of the second type — a victim of a special form of insanity?
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amhartley at 11:51 AM on 25 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
Scott Johnson, I don't know if you're reading the comments here, but this post is just about the most helpful one I've ever seen at SkS. And that's saying a great deal.
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hank at 08:23 AM on 25 January 2016IPCC overestimate temperature rise
Needs an update for 2015, if anyone has access to do that.
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MEJ at 21:48 PM on 24 January 2016Ted Cruz fact check: which temperature data are the best?
Thanks Tom for the more detailed info on the lag time between the satellites detecting the heat. Makes sense. It will be interesting to see the RSS data move up as it begins to detect it. Off course we pretty much walk about the surface of the Earth so surface temperature is what we live in not the troposphere 7 -10 klms above us. Thanks for all the info. Best regards MEJ
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Tom Curtis at 20:23 PM on 24 January 2016Ted Cruz fact check: which temperature data are the best?
MEJ @23 & 24, arguably the largest El Nino since 1950 occurred in 1997/98. As a result the GISTEMP Land Ocean Temperature Index set a new global temperature record of 0.47 C, a record it broke in the following year with a 0.63 C annual average (both relative to a 1951-1980 baseline). In contrast, RSS TLT only showed a distinctly non-record 0.1 C, only just shading 1987 and beaten by 1995. It then went on to a massive 0.55 C in 1998. (Records relative to a 1979-1998 baseline.) The reason for the very low temperature in 1997 relative to 1998 was the lag.
2015 is also arguably the largest El Nino since 1950, although I think it is smaller than 1997/98. Of course, there is a strong possibility that it will be referred to as the 1015/16 El Nino in the future. Regardless, the most comparable temperature from the 97/98 El Nino with which to compare the 2015 TLT temperature is 1997, which was not a record year. Well, at 0.36 C, 2015 isn't a record in the TLT series either, but it is a lot warmer than 1997, and is only beaten by 1998 and the 2010 El Nino year. Further, the most recent montly temperature (0.54 C) is very comparable to the 1998 annual record (0.55 C) and very close to most months in the 97/98 ENSO period as well.
So, the reason why 2015 is not a record in the TLT temperature series, while it is a record in the surface temperature series is very clearly the greater lag in response to ENSO events in the mid troposphere. The leaders of the denialist pushback against the extraordinarly warmth in the surface record for 2015 know this very well.
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MEJ at 19:38 PM on 24 January 2016Ted Cruz fact check: which temperature data are the best?
Thanks Moderator. I read it till my brain hurts. I read the post and watched the video. Cool to see Dessler and Mears interviewed. I also read the link John Hartz posted above which also included UAH satellite data. Thanks for that John.
Oh, okay I have not understood SURFACE TEMPERATURE as opposed to Lower Troposphere Temperature (TLT). Two different places. One we don't even live in. That is my mistake. Add in the inaccuracies inherent in satellite data in the video. Also as I presume you are alluding to there was a 'lag time' for the heat from El Nino in 1998 being detected in the TLT by satellite readings.Ok got it
Thanks
MEJ -
MEJ at 17:56 PM on 24 January 2016Ted Cruz fact check: which temperature data are the best?
Hi everyone. If I could get some help understanding why the Remote Sensing Systems (RSS) satellite data does not indicate 2015 as the hottest year on record.
The graph seems to show quite plainly 1998 as the hottest year and even 2010 as being hotter than 2015.
If I was to look at this graph I would say (possibly wrongly) 1998 far outsrips 2015 as the hottest year on record.
Thanks for any help understanding this.
Regards
MEJModerator Response:[PS] Um, that is largely what the article is about. Did you read it? 2015 is the hottest surface temperature on record (we dont live in the TLT). I would also watch this space if lag in response to El Nino in troposphere follows previous pattern.
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Glenn Tamblyn at 16:58 PM on 24 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
DS
"Not fully sharing your knowledge and understanding with others can give you a competitive advantage. "
One of the creative ways to lie"Tell the Truth. But Not All Of It"
Robert Heinlein
And yeah, Susan Cain's book is awesome. -
Digby Scorgie at 13:27 PM on 24 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
They are not climate skeptics. They are climate-change deniers.
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tcflood at 10:50 AM on 24 January 2016It warmed before 1940 when CO2 was low
@35 - 37 in response to 34
Thanks for the references and comments. Now I can give a more informed answer to the question.
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Tom Curtis at 09:43 AM on 24 January 2016It warmed before 1940 when CO2 was low
Kevin C @36, this is the relevant image from the article to which you link:
The right hand series of panels is ERSST v4-v3b. In it land temperatures are cancelled out and consequently not shown. The middle column of panels (ERSSTv4) however, does show land temperatures. In particular, it shows a very warm Chile plus Argentina, more or less adjacent to the unusually warm south east Pacific temperatures. Further, checking the 250 km resolution, meteorological station only map for the 44-45 period at Gistemp shows an off shore (island) meteological station of the coast of Namibia or Angola which again shows unusual warmth. Finally, the west coast of Australia is warm, although not exceptionally so in the 250 km resolution GISTemp map. These correlations to the warm pools in the SH in that period suggest those warm pools are not, or at least not entirely artifacts.
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Kevin C at 09:06 AM on 24 January 2016It warmed before 1940 when CO2 was low
tcflood: The narrow WWII peak itself is almost certainly spurious. It only shows up in the SST data, and particularly in ERSSTv4. There are very substantial known changes in SST measurement practices during WWII, which are hard to correct for completely. Hansen discusses it here.
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One Planet Only Forever at 07:47 AM on 24 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
nigelj,
More important points about the Satellite record are:
- The satellite temperature values do not measure the surface temperature.
- The result of increased CO2 concentrations is understood to be a more significant warming of the surface, under all the CO2, than the warming that would occur up in the atmosphere.
- The satellite data may be less reliable than surface temperature data for a number of reasons.
People like Cruz who try to make claims based on the satellite data are likely to understand the above points. They deliberately do not want to more fully inform others of what they are aware of (typical debate, legal, political and economic tactics)
Not fully sharing your knowledge and understanding with others can give you a competitive advantage. Especially if scientific investigation for political marketing purposes indicates that a significant portion of the population are willing to be easily impressed by misleading marketing claims or outright lies.
The power of being able to 'create impressions' began trumping the significance of the 'actual substance' of an issue in the late 1880s (Pointed out by Susan Cain in "Quiet: The Power of Introverts in a World That Can't Stop Talking"). That is obviously something that needs to change (contrary to desires to prolong or expand many developed damaging and unsustainable 'popular profitable pursuits of perceptions of prosperity').
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nigelj at 07:01 AM on 24 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
Cruz is either lying, or being misleading. He's intelligent enough to know using 1998 as a start point in the data isn't valid science.
This is particularly frustrating coming form Cruz, who sets himself up as a strong Christian with impeccable moral values, or at least aspirations to impeccable vales.
Its time the world stopped making excuses for people like Cruz. They should be utterly condemned for what the way they are acting, like utter charletans. Where's the media holding these people to account? Nobody has the intelligence or courage to do it, apart from a few websites like this one.
Not all climate sceptics are insidious people obviously, however the world is being held to ransom by a few fanatical climate sceptics. These people are towards the outside of the bell curve in terms of beliefs. Some of them may have some sort of personality disorder.
The satellite record shows 2015 was the third hottest year, according to UAH. However there is also a delay before el nino events show up fully in the satellite record. The 1997 - 1998 el nino didn't show up until mid 1998. Last years el nino may be the same, and wont fully show up until this year.
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Trevor_S at 18:28 PM on 23 January 2016The Little Ape That Could
veranda posts. I drove a small SUV with a trailer to a nearby town to hire a machine to excavate the post holes and return it the same day. The machine had a 25 horsepower (HP) motor. My car had a 130 kW engine - roughly 175 HP.
I think it was the Earh Day founder whom I will paraphrase, "All we have to do to ensure the complete destruction of the enviorment, is to keep doing exactly what we're doing now"
and to further mangle things, Tolstoy 'Everyone thinks of changing the world, but no one thinks of changing himself.'
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Tom Curtis at 13:43 PM on 23 January 2016A striking resemblance between testimony for Peabody Coal and for Ted Cruz
It occurs to me that part of the reason people buy the "satellites are more accurate" line is that they never see graphs of the raw data. I'm not sure where you could find a graph of the true raw data, and certainly would not be able to make one. But Po-Chedley et al (2014) have a graph of minimally processed data:
As I understand it, the top panel already has processing in the form of a rough alignment of means ot each satellites series. At least, it would be stunning if such a close allignment of absolute values was achieved in raw data from satellites. For comparison, here are the absolute alignment of satellite measurements of the solar constant:
Certainly similar problems of alignment are experienced by Earth observing instruments measuring the IR spectrum, and I see no reason why the microwave observing instruments (which operate on the same principles as the IR and solar observing instruments) should be any different.
Further, it is possible that the top panel in Po-Chedley's figure 3 also includes adjustments for problems with the hot target.
In any event, the transition between the top panel and the third panel is not a given. It represents serious adjustment to the data - and different teams disagree about how that adjustment is best done. As a result they also significantly differ about satellite data trends.
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Tom Curtis at 13:15 PM on 23 January 2016A striking resemblance between testimony for Peabody Coal and for Ted Cruz
gregcharles @3, there are (at least) two graphs of satellite data used in the hearing. The first, introduced by Happer, shows the average of RSS and UAH TMT data against the average of four ballon datasets. It is shown above in the OP.
The second, shown by Ted Cruz himself is of RSS TLT data from March 1997 to Novemer 2015, and is shown below:
It should be noted that Admiral Titley's point about the start point is valid, but limited. That is because the strong La Nina's in 2008 and again in 2001/12 contribute as much to the low trend as does 97/98 El Nino. Ergo, in 2016 when RSS finally shows the current EL Nino (which it currently does not due to a well known lag), the trend will still be below what would be expected if there were no short term variations.
I might add that watching the video was distinctly unpleasant. It leads me to the belief that the purpose of a congressional hearing is to give the chair of that hearing the chance to see just how many lies he can fit into a three minute speach. Virtually everytime Cruz stated something was the position of climate scientists, he got it egregiously wrong.
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David Lewis at 12:51 PM on 23 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
I assume Cruz is lying.
He is an accomplished debater. He made a name for himself starting at Princeton in 1992 when he won the Top Speaker award for them at the North American Debating Championship. When he went to Harvard Law one of his professors, Alan Dershowitz (a political liberal) said, "Cruz was off-the-charts brilliant". As Texas Solicitor General Cruz argued many cases before the US Supreme Court, winning more than he lost.
Because his argument against doing anything about climate change because it isn't happening is so weak, the first thought that comes to my mind is he is lying. Its just another debate to him. Top flight debaters can argue black is white, or white is black. It doesn't matter. He hasn't got much to work with in this climate debate, but he's giving it a shot.
He is cynically attempting to vacuum up the votes of people who actually believe NOAA, NASA, etc., just fabricate whatever it takes to contribute their bit to efforts of the global conspiracy of climate scientists who are all busy fabricating what they can so they can destroy the US economy or make their lawn die or whatever it is that they fear.
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davidsanger at 10:36 AM on 23 January 2016Thorough, not thoroughly fabricated: The truth about global temperature data
If you go to the doctor and he takes your temperature and it is 60°F you don't ask him to call the mortuary, you take another reading.
For a scientist to pretend that data readings are all correct, and to ignore known errors, would be dishonest - malpractice.
You make the observations and then you correct them as best you can.
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gregcharles at 10:35 AM on 23 January 2016A striking resemblance between testimony for Peabody Coal and for Ted Cruz
Was Cruz definitely using the TMT channel in the chart presented at "Data or Dogma"? I know he had trouble figuring out where the chart came from, before finally finding that it was RSS, but I never heard clearly whether it was TLT or TMT.
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One Planet Only Forever at 01:59 AM on 23 January 2016The Little Ape That Could
Glenn,
I appreciate the complexity of the issue and I really appreciate the time it takes to investigate, think about, develop and present an article like this.
Perhaps a simple statement could be added in this document mentioning that, unlike in the other species, there is a very broad range of individual magnitudes of impact among humans.
I believe that the different magnitudes of personal impact (not national or state/province per-capita levels) is a critical point to counter the misleading claims that the population number is the problem. The total number of people is only a concern. The combined total impact is the problem. Which makes the highest impacting individuals the real problem (and Global GDP has increased faster than population ... even Africa's GDP has risen faster than its population ... yet there are still many people who live incredibly brutal short lives ... the real concern)
And if a separate article is developed to more fully present the issue of the range of impact among humans, it could be mentioned that deliberate misleading marketing must be considered when attributing impact to an individual which would be presented in more detail in a separate item, if developed.
And that article about marketing can mention that Popularity and Profitability have fueled the increase of wealth and misleading marketing power of those who would willingly pursue unacceptable ways of benefiting any way they can get away with, distracting and distorting the results of the marketplace and democracy away from advancing humanity to a lasting better future for all, while creating unfustifiable impressions of advancement and superiority through the development of technological wonder toys for the wealthy and most fortunate that do not actually advance humanity. Those developments only create unsustainable impressions of advancement and superiority, while causing damage that no one who wants to enjoy benefiting from the activity and products wants to better understand the unacceptability of (especially not wanting to admit they do not deserve the perception of a Good Life that they were fortunate enough to get away with having developed).
This last point is the sad reality of places like Alberta where I live. Many people hate(not an overstatement of their attitude towards it) the idea of climate science and anyone who tries to promote better understanding of it because it really does mean they did not deserve the type of living and working that they developed through the past 30 years. They will "Believe anything that attacks or questions the better understanding they are actually able to understand".
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Nick Palmer at 00:51 AM on 23 January 2016The Little Ape That Could
Hi Glenn. I wonder if you ever encountered my writings on the land surface available per person that you used? Some of your words "Not all that land is usable; some is ice caps, mountain ranges, deserts" seem similar to mine.
I've been banging away in comment sections with these calculations for decades to counter those who try to claim that earth wasn't overpopulated because they pointed out that the global population could fit on the Isle of White or Rhode island etc. I first did the "reverse calculation" in 1966 for a school essay... -
SirCharles at 23:48 PM on 22 January 2016The Little Ape That Could
The arrogance is in the word "believe". It's not belief what has brought us forward, it's observation, comparing evidence and research, it's science. And before we realised we are just changing the climate of our fragile planet we already knew that we could even destroy the whole lot with nuclear weapons...
Here half a minute of global warming jazz => https://www.youtube.com/watch?v=b3VVt76DeoQ
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The Little Ape That Could
Mal Adapted #3:
The oxygen released by the cyanobacteria may also have destroyed almost all the methane in the atmosphere and as a result reduced the greenhouse effect enough to trigger the first and most severe episode of Snowball Earth.So, this is indeed the story of the little cyanobacterium that could!
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mancan18 at 20:45 PM on 22 January 2016The Little Ape That Could
Excellent post Glenn. It summarises much of what I have been reading over recent years.
It clearly illustrates that we humans through our sheer numbers and our ingenuity are now a terra-forming species with a global impact. Also, we humans are even more unique than we already were. With our broad scientific understanding and the technological developments that are a result, and our unravelling of the human genome and the new genetic engineering techniques that are being developed, we now have the ability to determine our own evolution. Unfortunately, our political systems, our economic policies, and our societies have not evolved to the point where we are capable of dealing with all the problems that these latest developments are causing. This is because the thinking of some very influential and powerful people is, unfortunately, stuck in the past as if they were still living in the world of 50 or 100 years ago when there weren't so many people and there appeared to be plenty for all.
Rising greenhouse gases in our atmosphere, our eroding of our planet, our polluting of the atmosphere and the oceans, and the impact that we are having on global ecosystems, is very similar to a time when people living in cities and towns would simply throw their effluent and garbage into the street. Many people died of cholera and other nasty diseases as a result. The only difference today is that the throwing of our effluent and waste is having a global impact and unlike the conservatives of several hundred years ago, some conservatives today don't seem to want to build the sewers.
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BilB at 18:20 PM on 22 January 2016A striking resemblance between testimony for Peabody Coal and for Ted Cruz
Oh, John, I feel your pain. To see Ted Cruz in action I fear for America. Curry, Happer and Christy were just plain embarrassing. Though I think Mayer, Schatz, Peters, Markin and Nelson deployed Titley powerfully and science shone over dogma.
I recently found (possibly through this site) James White's Colorado presentation to be a compelling expose of climate science clearly establishing the fundamental elements of climate change. White manages to sweep away the clutter of "complicated science" to reveal the undeniable basic principles.
https://www.youtube.com/watch?v=FmyBAUR7GZU
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Glenn Tamblyn at 17:36 PM on 22 January 2016The Little Ape That Could
Mal Adapted.
Yeah this a point many people don't get. Particularly many geologists. Life has been an integral part of the chemistry and geology of the planet for most of it's history. It doesn't matter whether it is cyanobacteria or evolved austrolopithicenes, any species that grows numerous and or powerful can have surprising impacts.
HK, neat graph. Visualising this sort of stuff is tricky.
OPOF
This was a difficult choice, all the things I would or wouldn't include. The more one adds the more the risk that I dilute the key message; 'that reaction of incredulousness about our capacity is misplaced'. -
One Planet Only Forever at 14:43 PM on 22 January 2016The Little Ape That Could
Very thorough and interesting presentation.
However, the point about population could be improved by categorizing the current human population in ranges of magnitude of impact of the individual. Not all humans are equal in impact (unlike the members of the other species listed ... there are admittedly some ranges of impacts among some of the domesticated species, particularly higher impacts for the industrial pharmaceutical factory farmed ones, the cheaper and quicker to produce - more profitable and popular - ones).
If that was done it would probably show that the 200 to 300 million (the number of humans 2000 years ago) highest consuming and highest impacting people (including their share of the impact of activities they invest in to benefit financially from) are quite likely to be responsible for more than 90% of the unsustainable consumption and damaging impacts.
If evaluated rigorously and rationally, including almost entirely attributing the consumption and pollution of stuff 'that wealthy investors profit from convincing people to desire (like plastic micro-beads and throw-away plastic)' to those wealthy investors it is likely that significantly fewer than 100 million people could be identified as being 'quite likely to be responsible' for more than 99% of the identifiable and quantifiable total global unsustainable over-consumption and negative impacts.
A person tempted to buy into an appealing misleading sales pitch could be considered to be a hapless victim of fraud, not able to be deemed to be significantly responsible for the impacts of what they were tempted into desiring - addicts need to be helped to break free from their damaging addictions, not be blamed for becoming addicted. The Pushers need to be targeted.
The number of successful pushers of damaging unsustainable over-consumptive addictions is the actual “Population Problem”.
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Tom Curtis at 12:24 PM on 22 January 2016Tracking the 2°C Limit - November 2015
As per the moderators suggestion, I have responded to angusmac across three posts elsewhere. I will make one point in response here, however, because it gets to the core of why angusmac raised HCO temperatures on this thread in the first place. To recap, angusmac argues that the MWP temperature should be used as the "preindustrial temperatures" for reasons sufficiently refuted above. His reason for doing so comes down to his opinion that, "...“1.669 °C” above the 1961-1990 mean [and MWP temperatures] ... does not sound nearly as bad as 2 °C". This in turn is related to his belief that "... many parts of the world exceeded the 2 °C limit [in the HCO] without any dangerous consequences and that these temperatures occurred when CO2 was at ≈ 280 ppm". The idea is that if 1.67 C above the 1961-1990 mean is not bad, then neither is 0.75 C (2015 average, HadCRUT4) and neither is 2 C above the preindustrial average. Ergo, rebaselining the 2 C guidline is justified to make that intuitively obvious.
Marcott 2013 allows us to see how flawed that intuition is.
Specifically, Marcott adds random variability to the stack of reconstructions used in the paper to make the annual scale variability of the reconstructions match actual annual scale variability. The result is an increase of 0.13 C to the standard error. It follows, that if we add 0.13 C to the standard deviation of the mean of the stack for each 20 year period in the full reconstruction, we get a good approximate measure of the potential range of annual temperatures for that 20 year period. Note that due to autocorrelation, if temperatures are low for a given year in a 20 year period (or century), in a specific member of the stack, they will not be high within that 20 year period (or with slight qualification, within that century). But because we do not know which member of the stack most closely approximate reality, the statistical data form all stacks gives us our best approximation of the temperature range. From that in turn we can calculate an approximate probability of a particular temperature in any given year:
The chart shows the probability of a given temperature (specified by year) in any given year over the Holocene. The green line shows the probabilty of 1.5 C over the 1961-1990 mean. It is consistently zero. Even 2015 tempertures are shown to be relatively rare in the HCO, though 2000-2009 temperatures were commonplace.
More interestingly, we can calculate the probability of those temperatures being reached at least once, in any year over a given period. For the period 5500-9500 BP, it is a near certainty that even 2015 temperataures will have been reached at least once. There is, however, only a 2% chance that temperatures reached 1.5 C above the 1961-1990 at any time in the HCO. The chance that it reached 2 C above preindustrial for even a single year is negligible.
It can therefore be seen that angusmac's assumption that high temperatures were commonplace in the HCO is simply false. We are very nearly at the upper limit of HCO temperatures. Nor is his assumption that HCO temperatures were always beneficial justified. Indeed, given that almost all agriculture was invented between 30 degrees North and 30 degrees South (and all was invented between 40 north and 30 south), and given that temperatures in that latitude zone have actually increased since the HCO, his assumption of beneficial effect is very shaky indeed.
Finally, for completeness, the probability of 1990-2009 twenty year average temperatures of the 950-1900 preindustrial baseline is 0.6%. The probability of 1996-2015 twenty year average temperatures of the 950-1900 baseline is just 0.03%. So much for natural variability being the cause.
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Tom Curtis at 11:33 AM on 22 January 2016Real Skepticism About the New Marcott 'Hockey Stick'
This is my final response on this page to angusmac's comment here. In that comment, in addition to the three points addressed above he draws attention to the fact that the 19th and 20th century spike in the Marcott standard mean of reconstructions is not robust (something pointed out by Marcott et al in the original paper). He reinforces the argument by comparing the final stages of Figure S3 to the equivalent Figure C8 from Marcott's thesis:
He writes:
"A difference of approximately 0.8 °C in the two versions of the reconstruction is presented in Figure 1 – yet they use the same proxies. Marcott et al do not address this significant difference by their “not robust” statement.
...
In light of the above discrepancies in Marcott et al (2013), I would not recommend it as a reasonable paleo reconstruction."
In the elided section, he adds the further, hypocritical criticism that Marcott's response to blog criticisms on a blog rather than formally through an corrigendum or explanandum published in the journal "...casts doubt on the robustness of the last 500 years of the reconstruction and perhaps even the entire paper". The double standard in not assuming that the failure of critics to formally publish their criticisms "casts doubt on the robustness" of those criticisms is breath taking. I will treat that "argument" with the contempt it disserves, and give it no further dicussion.
With regard to robustness, Tamino explained it first and best. It is entirely an artifact of the method of taking a simple average combined with the drop out of proxies towards the end of the record. Using other methods such as the method of difference (see Tamino's post), or the RegEM method used as an alternative method in Marcott et al, results in a much smaller, but robuts uptick occuring in the 20th century only:
Comparison of simple averages to the method of difference (or the RegEm method) shows the problem has little effect anywhere else in the reconstruction, and a scarcely discernible effect in the crucial years of the Holocene Climactic Optimum:
Given that angusmac is familiar with Marcott's Q&A at Realclimate, and even with Marcott's thesis, he must be familiar with this explanation of the problem, and ergo that it makes no relevant difference to the reconstruction in the HCO. Given that, I am surprised (to say the least) that he should raise this issue.
This, of course, does not explain the difference in the terminal section of the stacks generated for the paper (S3) and the thesis (C8). What angusmac does not show is the difference between Figure C8 and Figure C9 of the thesis:
As can be seen, calibration issues in just one proxy were able to make a significant difference to the robustness of the reconstructions through the HCO. Those issues were resolved in the paper, and the proxy consequently is used in the paper without problems. While that proxy (ODP 984) terminates around 1400 AD, and therefore does not contribute to the lack of robustness of the terminal period, it is likely that similar improvements in calibration and/or terminal dates explains the difference between C9 of the thesis and S3 of the paper with regard to the final two centuries.
Comparison of C9 and S3 shows the problem to only relate to the final two centuries which are not the point of the reconstruction, and which are not used to calibrate reconstruction temperatures to modern temperatures (which is done indirectly via the Mann 2008 reconstruction of temperatures over the last 2000 years). From this it follows that there is no basis in this data to doubt the HCO reconstruction from Marcott et al.
Nor is any substantive reason advanced to show the changes in data handling with regard to calibration and possibly terminal dates between the two does not represent an improvement. As it makes no difference to the substance of the reconstruction that is sufficient answer IMO. If it does not satisfy angusmac, he can do the necessary leg work by enquiring of Marcott re all the precise differences between thesis and paper among which the full explanation must be found.
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adrian smits at 11:28 AM on 22 January 2016The Little Ape That Could
I find it interesting that you were born in 1957. The radiosondes developed the worldwide network in 1958. Since that year, they show .16 degree of warming in total. When you were talking about measurement I thought that might be an interesting factoid.
Moderator Response:[PS] Sloganeering and dangerously close to offtopic. Care to explain why you think that "factoid" is interesting? Actually, do so on an appropriate topic (such as here - where RATPAC graph does not appear to support your assertion)
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Tom Curtis at 10:08 AM on 22 January 2016Real Skepticism About the New Marcott 'Hockey Stick'
Continuing my discussion of Angusmac's comment here:
Point (3) clearly misunderstands the nature of the Marcott reconstructions. (The misunderstanding is quite common among people who discuss climate science on the internet.) Specifically, while the mean of the stack of reconstructions has a resolution of approximately 300 years, the reconstructions themselves (as shown in figure S3, see Comment 101 above) have a resolution of 20 years. They are therefore quite appropriately compared to decadal temperatures. Further, in generating Figure 3 (see comment 101 above), which is the crux of Marcott et al, Marcott et al added noise to the reconstructions so that their variability matched the annually resolved Mann 2008 reconstruction. The statistical distribution is, therefore, quite appropriately compared to annual temperatures.
Given this, it is reasonable to criticize graphs that show only the stack mean vs modern temperatures. The falsely give the impression that we are experiencing temperatures never experienced before since the invention of agriculture. Rather, modern twenty year averages should be compared to the individual reconstructions in the stack, like this:
As you can see, even the 1996-2015 average was probably experience many times (if briefly) in the Holocene, but we are pushing towards the upper temperature limit of the Holocene. More significantly, the rate of increase of temperature over the last century is certainly in the highest 5% of holocene temperature trends, and may well be unprecedented. It is also ongoing.
More later.
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The Little Ape That Could
Glenn:
Your article inspired me to create this pie chart of the Earth’s land mammals based on a comment by Andy Skuce in December.
If I counted all the squares correctly, wild land mammals represent less than 3% of the total mammalian biomass on land today. And that isn’t the whole story, as many of the remaining populations of wild land mammals are also harvested by us. For instance, humans are the most common predator of the moose in Norway (about 36,000 shot every year), so even the tiny, green part of the pie chart is largely controlled by humans.
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Mal Adapted at 07:55 AM on 22 January 2016The Little Ape That Could
Up until about 2.5 billion years ago, there was no free oxygen on Earth, either in the oceans or the atmosphere. All life was anaerobic. Then cyanobacteria evolved. Cyanobacteria, formerly call blue-green algae, photosynthesize by using hydrogen atoms from water molecules to reduce CO2, releasing molecular oxygen (O2) as a "waste" product.
For millions of years, the newly-released molecular oxygen immediately combined with reducing substances in the oceans, but eventually those were used up, and free oxygen began to accumulate.
Free oxygen was toxic to the anaerobic life dominant at the time. A mass extinction ensued, and the only survivors were those that could protect themselves from the corrosive effects of O2. Eventually aerobic metabolism evolved. Aerobic metablism uses molecular oxygen to convert much more of the chemical energy in organic compounds to energy. Life again spread to occupy the globe.
This is the story of the little cyanobacterium that could.
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John Hartz at 05:34 AM on 22 January 2016Ted Cruz fact check: which temperature data are the best?
Recommended supplementary reading:
Thorough, not thoroughly fabricated: The truth about global temperature data by Scott K Johnson, Ars Technica, Jan 21, 2016
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John Hartz at 05:30 AM on 22 January 2016The Little Ape That Could
Glenn: If you expand this excellent article in the future, you may want to add a new section on the amount of manmade plastics that has been created by humans and released into our biosphere. For example...
By the Year 2050, There Will Be More Plastic Garbage in the Ocean Than Fish by Tom McKay, Science.Mic, Jan 19, 2016
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Cooper13 at 03:54 AM on 22 January 2016The Little Ape That Could
Some fantastic perspective here on our overall impact/footprint on the planet. Thanks for posting this.
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Glenn Tamblyn at 16:51 PM on 21 January 2016It warmed before 1940 when CO2 was low
tcflood
These graphs, also from GISS, show different regions - Norther exa-tropics, tropics and southern exa-tropics. Quite different pictures.
Also this paper might be interesting, particularly figure 11. -
tcflood at 16:09 PM on 21 January 2016It warmed before 1940 when CO2 was low
Whenever I show this plot in a talk, someone invariably asks about the cause of the maximum around 1945. The only info I can find, including your posting above, talks about the general increase from about 1910 to 1945, followed by aerosol cooling until around 1975.
This 1935-1950 feature certainly looks real so the only thing I can say to the questioner is that I am not aware of a specific answer from climatologists, but I suppose that the pronounced bump is an accident of natural variability. The questioner usually appears as unsatisfied as I feel. Do any of you have a better answer?
Moderator Response:[DB] Resized image breaking page formatting.
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Tom Curtis at 15:26 PM on 21 January 2016Real Skepticism About the New Marcott 'Hockey Stick'
Angusmac criticizes the Marcott reconstruction here, saying (in part):
"Rob, I agree that the conversation has veered off course for this comment thread but I do wish to make the following comments regarding Marcott et al (2013) that are relevant to baselining preindustrial temperatures:
- Marcott et al state that their results indicate that “global mean temperature for the decade 2000–2009 [HadCRUT3] has not yet exceeded the warmest temperatures of the early Holocene (5000 to 10,000 yr B.P.).” Therefore, if we were to use their reconstruction, we would be near to the Holocene peak.
- 80% of the Marcott et al proxies are derived from marine archives and consequently would underestimate global land-ocean temperatures. Consequently, the Marcott et al results should be adjusted upwards for an apples-for-apples comparison with land-ocean temperatures, as suggested by Glenn Tamblyn@9.
- Proxies tend to have multi-decadal to centennial resolutions and should not be compared directly with annual instrumental temperatures. Kaufman et al (2013) consider this by presenting the most recent 30-year period (1983-2012) from HadCRUT4 as shown by the star in Figure 2. However, a good case could be made for using a longer period for the instrumental mean when comparing it with proxies that are of centennial resolution e.g., Marcott et al (2013)."
Point (1) should be commonplace, although due to a common misinterpretation of Marcott et al, it is not. The misinterpretation is that the bold line in the center of the 1 sigma uncertainty interval in Marcott et al is the "reconstruction", whereas it is just the mean of an ensemble of reconstructions. Marcott et al state no preference among that ensemble as to which is the "real" value, so therefore all members of the ensemble must be given equal weight. All, or nearly all members of the ensemble frequently lie higher than the ensemble mean, and often much higher. It follows that temperatures greater than even 2015 are far more likely than not to have occured in the Holocene Climactic Optimum, and indeed may have occurred close to 1 in every 20 years over the period 5500 to 9500 BP.
Point (2), on the other hand is at best ill informed nitpicking. Ill informed because it assumes the differential rate of heating between land and ocean which leads to cooler oceans in a warming climate (and warmer oceans in a cooler climate) will be a significant factor over multi-centenial periods. For the Marcott mean value, the time resolution is 300 years, at which resolution the difference between land and ocean would be effectively nil. (This contrasts with the case for the much smaller resolution of reconstructions of the MWP.)
Nitpicking because while sea temperature proxies are 80% all proxies, the sea surface is 70% of global surface area. That is, sea surface temperatures are only overrepresented by 14.3%. This evidently creates a problem for somebody prepared to overlook that sea surface temperatures were underrepresented by 45.7% in the Lundqvist analysis that he prefers. Further, nitpicking because again in Marcott et al, NH proxies are again overrepresented (as is typically the case in reconstructions). Marcott el al write:
"The Southern Hemisphere is represented by fewer data sets (n = 11) than the equatorial (n = 33) and Northern Hemisphere (n = 29) regions, providing fewer constraints on characterizing the variability in our reconstruction for this region."
Despite Marcott's phrasing, the SH extratropics is well represented, with 15.1% of proxies for 18.3% of the surface area (17.5% under representation), but the NH extratropics has 39.7% of the proxies for 18.5% of the area (a massive 114.6% over representiation). Meanwhile tropical regions, with 45.2% of proxies for 63.7% of the area, are also under represented (29.1% under representation).
As can be seen below, NH temperatures rose much higher in the Holocene Climatic Optimum relative to tropical or SH temperatures:
As it turns out, the most under represented area relative to the proportion of the Earth's surface shows lower temperatures over the Holocene Climactic Optimum, while the area with the greatest early holocene warmth is massively over represented.
These biases are far more likely to impact the final reconstruction than are the relatively minor land/sea bias pointed to by Angusmac. Further, they bias in the opposite direction to his presumption regarding the land/sea bias, and so would surely cancel the effect (at least).
Finally, as it happens Marcott et al checked for the effect of biases against a simple model:
Clearly their methodology was sufficiently robust to eliminate all but a small part of the warm bias we would expect from looking at proxie locations alone.
I am currently short of time, and will discuss point three and further criticisms later.
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Digby Scorgie at 12:57 PM on 21 January 2016The Quest for CCS
Tom
I'm essentially in agreement with you. I know it has for some time been technically and economically feasible to fix the climate problem. And of course it is politics blocking progress.
Glenn and OPOF
In belated reply to your points, I have to say that I agree with much of what you both say as well. Everything depends on our rate of change to renewables, which depends not just on technology but also on societal attitudes. Fixing the socioeconomic system would help. We shall see.
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sailingfree at 11:19 AM on 21 January 2016A striking resemblance between testimony for Peabody Coal and for Ted Cruz
Thanks.
btw, the 2015 temperatures are now at NOAA http://www.ncdc.noaa.gov/cag/time-series/global
2015 is a scorcher, deniers better jump right to the stratosphere data.
Moderator Response:[PS] Fixed link. Please use the link tool in the comments editor to create links.
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nekroluma at 07:22 AM on 21 January 2016It's the sun
limited selection set obfuscation and dulicity, it is UV class C radiation that is melting the ice, anyone can take a simple UV measurement and substantiate this reality. Why did UV class C suddenly start reaching the surface? the earths high altitude ozone layer is dissolved by CFC and HFC contamination only by oil refining unrestricted pollution since 1980 when the EPA was destroyed by reagan appointee james watt. So the only country with real air standards was compromised.
Moderator Response:[PS] Welcome to Skeptical science. Please take the time to review the Comments Policy and ensure future comments are in full compliance with it.
Firstly, you appear to be offtopic. I think this would be better under "its ozone". Use the search button in top left to find appropriate topics. Secondly, note the requirement to back claims. In particular, the claim that UV_C is melting ice caps is contrary to published science. The association of CFCs and HFC with oil refining is also unknown to me.
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gtarestoration at 05:57 AM on 21 January 2016Corals are resilient to bleaching
Corals are bleaching across all the world’s oceans in only the third die-off of its scale in history, scientists have revealed.
El Nino and a Pacific warm water mass known as “The Blob” are combining with human-caused climate change to drive record high ocean temperatures.
These hostile conditions are expected to deplete more than 38% of the world’s reefs by the end of 2015, according to the US-based National Oceanic and Atmospheric Administration (NOAA).
Recent damage to corals in the Caribbean follows bleaching in the Pacific and Atlantic oceans earlier in the year, confirming the phenomenon as global in scope.
It has knock-on effects for species that rely on healthy corals for food, as well as for people who make a living from tourism or fishing.
“What really has us concerned is this has been going on for a year and is likely to last another year,” said NOAA coral specialist Mark Eakin.
The El Nino weather system, characterised by a period of warm water across much of the Pacific, is forecast to remain strong until early 2016.
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knaugle at 05:10 AM on 21 January 2016Ted Cruz fact check: which temperature data are the best?
@BarryYou are correct. I did the search you suggested and sure enough he was named BY WUWT of all sites! :)
And along the way I found a rather scathing article by Tamino about some of A.W.'s accusations leveled at James Hansen and others.
Thank you.
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