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.

Planting Trees Won't Help

"In my view the carbon dioxide has no effect on warming anyway."

Perhaps in your world then the radiative physics of anthropogenically-derived CO2 differs from that already in the carbon cycle. How wonderful. For those of us in this world it is a different story. Please note that unsupported assertions lacking source citations are generally ignored or treated as spam.

new boy on the block at 14:26 PM on 3 November 2011

10 Indicators of a Human Fingerprint on Climate Change
i am new to the debate and if my point has been covered elsewhere i would appreciate a link. do we sufficiently understand the driving forces behind the cycle of ice ages and subsequent warming to state categorically that co2 from the burning of fossil fuels is the principal cause of the current warming?

muoncounter at 14:20 PM on 3 November 2011

CO2 – Some facts, figures and outcomes
Carbon S#19 Here's evidence. van der Werf et al 2009: carbon emissions from deforestation and forest degradation have been estimated to account for about 20% of global anthropogenic CO2 emissions That appears to be an average; the most recent estimate shown in Figure 1 in that paper was for 2006: Deforestation ~1.5 Pg C/yr, fossil fuels ~7 Pg C/yr. It's good practice to substantiate one's commentary - especially if you're interested in building credibility.

scaddenp at 14:14 PM on 3 November 2011

CO2 – Some facts, figures and outcomes
Carbonskeptic. The evidence is from carbon isotopes (not to mention some basic accounting). Deforestation is another anthropogenic change, but again the isotope data says fossil fuel more important. See this article for more detailed explanation and references to the science.

Bob Loblaw at 14:06 PM on 3 November 2011

Climate's changed before
lancelot: it is not easy to measure surface radiation fluxes well. Last I looked, a system that will meet BSRN guidelines will cost you around $100k in equipment and sensor costs. BSRN is intended for long-term climate monitoring, and accuracy requirements push modern technology. If you want a very long read (and want to download quite a few megabytes of manual), the BSRN web site has a link to their Operations Manual. (Don't click the link unless you want the full manual!) Be prepared for a huge whack of technical discussion of sources of error, but before anyone decides "we can't measure radiation" keep in mind that the BSRN goals for accuracy are set very high (in the 1 W/m^2 range). It's the Rolls Royce of radiation measurement, not the Chevrolet version. It's part of the Global Energy and Water Experiment (GEWEX), and has been designated as the radiation observing system for the Global Climate Observing System (GCOS). Sphaerica: Please don't try to tell me that it can all be done by satellites. They give great spatial coverage, yes, but accuracy of surface radiative fluxes can't come close to good surface-based measurements. BSRN provides data at one-minute intervals, 24 hours per day, 365 days a year. A literature search for BSRN references will probably provide you with mostly satellite papers, all desperate for good ground-truth data.

macoles at 13:49 PM on 3 November 2011

Is there a case against human caused global warming in the peer-reviewed literature? Part 1
It would be worth clarifying that Jo Nova's real name is Joanne Codling (perhaps in her hyperlink?), as presumably she wouldn't be able to use her stage name in a peer reviewed journal :)

mikeh1 at 13:36 PM on 3 November 2011

Is there a case against human caused global warming in the peer-reviewed literature? Part 1
Here is one that you can remove. The one publication linked to William Kininmonth is a Heartland Institute paper. How does that qualify as being from a peer reviewed scientific journal? The link is hosted by the Australian Climate Science Coalition, an Australian climate denier group. From Sourcewatch. The Australian Climate Science Coalition (ACSC) is a climate change skeptics website created by the the Australian Environment Foundation (AEF), a spin-off group created by the the corporate funded think tank, the Institute of Public Affairs.

muoncounter at 13:36 PM on 3 November 2011

Climate's changed before
lancelot#255, quoting Tom C#243: "More importantly, it is far from clear that this is a global phenomenon." Alpert et al 2005 supports Tom's observation: we show that this phenomenon, widely termed global dimming, is dominated by the large urban sites. The global-scale analysis of year-to-year variations of solar radiation fluxes shows a decline of 0.41 W/m^2/yr for highly populated sites compared to only 0.16 W/m^2/yr for sparsely populated sites (<0.1 million). Since most of the globe has sparse population, this suggests that solar dimming is of local or regional nature. Move over Urban Heat Island, here comes the Urban Dim Island!

Bob Loblaw at 13:33 PM on 3 November 2011

Pielke Sr. and SkS Dialogue Final Summary
Rob@59 I'm not sure why you think the processes in the post How Increasing Carbon Dioxide Heats The Ocean (your link has an extra " at the end) contradict what vitull has said: - radiation reaches the surface from the atmosphere. Visible light will penetrate the water surface and be absorbed at depth, while IR will be largely absorbed right at the surface. (Energy gain to ocean) - visible light will be (partly) reflected at the surface and at depth, and IR will be emitted upward at the surface. (Energy loss from ocean) - turbulence in the atmosphere will carry heat and water vapour either towards or away from the surface (mainly away). This is convective transfer (in normal physics-speak). (Water vapour represents energy because it takes energy to evaporate the liquid). - turbulence within the ocean will transport heat away or towards the surface. This is convective transfer. - the viscous layer at the immediate ocean surface that is discuss in the other post does not have turbulence, but that is where conduction plays a role. Conduction can be up or down, depending on conditions (local gradient), but would be predominantly upward (from ocean depth to surface). Have I left something out? All these fall into victull's "radiation, conduction, and convection". I'd agree that the dominant global, long-term mean source of energy addition into the ocean is radiative, but on a local time-dependent scale, you can have net radiative loss to the atmosphere (e.g. at night), turbulent transfers from the atmosphere as net gains (warm humid overlying air, with condensation), and heat conduction across the viscous layer directed downwards. Perhaps you took victull's statement as one indicating long-term averages, as opposed to my interpretation of it as a general statement of possibilities? Perhaps my comment on the surface energy balance in that post is useful.

CarbonSkeptic at 13:30 PM on 3 November 2011

CO2 – Some facts, figures and outcomes
You say "The largest source of increasing CO2 in the atmosphere since 1850 is from the burning of fossil fuels ..." I ask what evidence you have that (a) such increases are larger than natural increases and (b) such increases are larger than increases due to deforestation which not only adds CO2 from burn-offs but also, far more so, from the resulting reduction in photosynthesis.

Lazarus at 12:05 PM on 3 November 2011

Fred Singer Denies Global Warming
A week ago the British Politician Roger Helmer, Member of the European Parliament and climate skeptic posted the email from his 'good friend' Singer on his blog; http://rogerhelmermep.wordpress.com/2011/10/27/the-scientific-finding-that-fails-to-settle-the-climate-change-debate/ I felt the need to comment, and still am.

Bob Lacatena at 11:58 AM on 3 November 2011

Is there a case against human caused global warming in the peer-reviewed literature? Part 1
2, Gringo, I'd guess that the error would more likely be an editorial one than one of review. That is, review probably incited the new version of the paragraph, but then whoever edited the text mistakenly inserted the new paragraph and forgot to remove the old. A pretty harmless, human mistake, IMO.

Tom Curtis at 10:39 AM on 3 November 2011

Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
Lancelot @29, you specifically ignore the first, and rapid decline from 1800 to 1815. To the extent that that represents a signal in global temperature rather than an artifact of the limited regional coverage, it is likely that that decline comes from an even higher peak prior to 1800. That is because the Dalton Minimum, the presumed cause of the decline, began in 1790, and followed a peak in solar activity (as determined by sunspots) greater than any in the 20th century other than 1950.

Consequently, the presumption of your first post of "a gradual and fairly uniform (if smoothed) global rise from at least 1800* to 1939". The evidence from BEST is of a major temperature excursion early in the record followed by a gradual rise from 1850 to 1910, followed by a rapid rise to 1940, a steady declind to the 1970's, and then a still more rapid rise to the 2000's.

Tom Curtis at 09:51 AM on 3 November 2011

CO2 measurements are suspect
MewCat100 @45, your point (4) lacks clarity. CO2 is approximately evenly distributed with altitude by concentration, as you note in (5). We do not need to reason that out, but can consult actual measurements: C)2 concentration with altitude, Colorado USA:

Seasonal variation of CO2 concentration, Russia:

CO2 concentration in upper troposphere and stratoshpere:

(Click on images for more detailed discussion) However, the small changes of CO2 concentration with altitude are not enough to induce the temperature variations with altitude. They are primarily a function of convection which induces the environmental lapse rate. This is modulated by relative humidity, and by winds which can bring warm or cold air in from other locations. I do not see,however, what this has to do with the question posed in the OP's title.

Gringo at 09:46 AM on 3 November 2011

Is there a case against human caused global warming in the peer-reviewed literature? Part 1
Regarding Energy & Environment's review process (or rather lack thereof), David C. Archibald's "Solar Cycles 24 and 25 and Predicted Climate Response" (PDF) is a good example. At the top of its page 31 there are two paragraphs which are almost identical and where the author clearly forgot to delete either of them. If the paper was reviewed at all, let alone by qualified reviewers, surely that double paragraph would have been spotted by someone? Or am I too naive to believe a 'scientific journal' which claims to "act as a forum for constructive and professional debate" should spot and correct such basic errors?

Rob Painting at 09:09 AM on 3 November 2011

Climate's changed before
Lancelot -"In China one would expect a decrease in net irradiance received due to aerosols. I will have to take your word that the paper describes a decrease in actual sunlight hours since 1974, as I don't have access to it" There are numerous papers freely available on the topic. Try Google scholar. The indirect effect on aerosol formation is not what most people may think. In extremely polluted areas the sulfate particles reach a break-even point and start to warm clouds so much they begin to evaporate. This is small relative to the dimming effects, but it is a saturation point of sorts.

Moderator Response: [Sph] Google scholar = http://scholar.google.com, a useful tool for searching specifically for scientific papers by keyword, author, and date range.

michael sweet at 09:02 AM on 3 November 2011

Fred Singer Denies Global Warming
Milka: You are wrong when you say "no-one denies the link between tobacco and lung cancer anymore" Dr Richard Lindzen (the climate skeptic from MIT) has testified in court that there is no link and maintains that argument today. this is the company the "skeptics" keep.

Bob Lacatena at 09:01 AM on 3 November 2011

Climate's changed before
256, lancelot, No worries! I appreciate the interest in the science! The main point is that the science now is all about microbes and potential impacts on cloud formation, but there are no signs whatsoever that this translates into any effect on global climate, let alone a non-negligible warming effect related to current climate change. That's just a big leap, that isn't warranted by the state of the literature. From the article you linked to (emphasis mine):

These data add to a growing body of evidence that biological organisms are affecting clouds, notes Anthony Prenni of Colorado State University in Fort Collins, an atmospheric scientist who did not participate in the new studies. Right now, he cautions, “We still don’t know on a global scale how important these processes are.” But research into microbial impacts on weather and climate is really heating up, he adds, so “within a few years, I think we’re going to have a much better handle on it.”

So it's very interesting, yes. So are any number of avenues and subjects on which the media has yet to report. But it's of no interest in climate science (to me, at least) at this time. It's about weather, not climate.

lancelot at 08:51 AM on 3 November 2011

Climate's changed before
Ah, page 6 now.. apologies for missing the latest posts when I wrote 255. Sphaerica, I am not trying to put down scientists, and I am sure you have even thought about fairies! But I have not been able to find any consideration of micro-organisms/clouds in the IPCC reports, and there are some interesting papers on the subject, such as http://www.wired.com/wiredscience/2011/05/microbes-make-rain/ Hence my question. I note the difficulties with making ground level (or sea level) measurements. Thanks again.

lancelot at 08:36 AM on 3 November 2011

Climate's changed before
Tom Curtis 243; Could I add: You wrote: "More importantly, it is far from clear that this is a global phenomenon. Certainly in China the trend has been in the opposite direction towards less sunlight hours. A similar reduction of sunshine has been found in Switzerland, so the observed increase in the UK is not even a Europe wide phenomenon, let alone a world wide phenomenon." The Swiss study abstract quotes "general decrease of sunshine duration through to the mid 1980's". That doesn't seem so far off from the general decrease to around 1979-83 on the Met Office chart. (Just eyeballing here). Some data divergence perhaps due to varying definition of 'sunshine' measurement? So perhaps some common ground UK-Swiss? In China one would expect a decrease in net irradiance received due to aerosols. I will have to take your word that the paper describes a decrease in actual sunlight hours since 1974, as I don't have access to it. DB: Wow!- thanks for the Wild 2009 copy, really kind of you.

Rob Painting at 08:30 AM on 3 November 2011

Climate's changed before
Lancelot -" Is that because readers are much too kind to lambast me for my stupidity in thinking that the airborne biosphere might(repeat might!) have a part to play in climate?" There is a considerable literature on the biogenic aerosol effect (naturally-occurring particles such as pollen, sea salt, leaf fragments etc seeding cloud formation). I've read a lot of papers on aerosol formation in the Amazon rainforest region, for starters. What is it you think they (biogenic aerosols) are doing? And how do you come to the conclusion the IPCC doesn't know about the published scientific literature?

Bob Lacatena at 08:28 AM on 3 November 2011

Climate's changed before
250, lancelot, I mentioned aerosols because your point is not about cloud forcing (whether you realize it or not), but about total solar radiation received at the surface. You are presuming that cloud cover changes are a possible and likely cause (less clouds = more sunlight = more warming). You are then taking it a step further and saying that well, okay, it may not be GCRs, but maybe it's something else. That's magical thinking. That's hoping to find a cause, and then after the fact looking for a cause of the cause. More to the point, I included aerosols because they can have the same effect as clouds, by reflecting incoming sunlight. Indeed, Hansen proposes this for a reason that warming is not as great as it should be. It's also a reason that the loss of the Glory satellite was a big blow to advancing climate science. But a decrease in such reflective aerosols (due, for instance, to improved pollution controls) could in the same way raise temperatures. Aerosols (depending on the type) can also have the opposite effect, by absorbing more sunlight and increasing warming, so an increase in such aerosols could warm the earth. The point is that scientists are not stupid. They are looking at all of these things and giving them their due. On micro-organisms, stony silence and kindness concerning stupidity... ummm, sorry, sort of. When you mentioned it I did look into it, and there do seem to be some very, very interesting papers on the subject of micro-organisms and their impact on cloud formation. But I honestly didn't think for a moment you were serious about it. But... while this is an area of interest to the scientists working on it, as of now: a) There is no strong, well-defined or reasonably serious mechanism that turns micro-organisms into a major player in changes in cloud formation in the last 30 years. b) More importantly, no change in micro-organisms has been identified or even proposed that would suggest that something has happened in the last 30 years to trigger warming. Again, it's a case of hunting for an alternate cause when there is no reason to do so, and then in turn still needing to find a cause of the cause. Could it be clouds? We have no reason whatsoever to think so (and don't think scientists have not been measuring cloud cover, they have). Could it be clouds caused by micro organisms? We have no reason whatsoever to think so. Could it be clouds caused by falling fairy wings, as a result of an unexpected increase in the desiduous-winged fairy population? We have no reason whatsoever to think so. [Sorry if that last sounded snarky. It wasn't meant to be. It was meant instead to show that science must work by going from observation to hypothesis to experiment to confirmation/refutation. And can not work simply through "but what if..." followed by any and every idea that anyone could consider, simply because they don't like the ideas that we do have, for which we have evidence, and which logically and consistently explain the entire picture without the addition of fairy wings.]

Albatross at 08:14 AM on 3 November 2011

Richard Milne separates skepticism from denial
Ian @57, Guess who is McKitrick's BFF? Yes, Steven McIntyre.

Bob Lacatena at 08:10 AM on 3 November 2011

Climate's changed before
250, lancelot, Measuring energy received at the surface may seem straightforward, but as I said before, it is most certainly not. You must account for: 1) Local, low lying and potentially transient effects (smog, fog) 2) Coverage... how do you do it on the oceans, which cover 70% of the earth? Deserts? Inhospitable countries? 3) Altitude... radiation will be higher for measurements taken at higher altitudes 4) The past? How do you know what happened before you get your network set up? To what do you compare your new values? All of the problems that plague the observational surface temperature record apply as well to measuring sunlight. It's just not as easy as it sounds, especially when a satellite can do that and more for less money with less effort and more consistency.

Bob Lacatena at 08:06 AM on 3 November 2011

Climate's changed before
250, lancelot, To clarify, however, the references to clouds in the AR4 do not give any credence whatsoever to the idea that changes in cloud cover are responsible for the modern warming trend. This is in no way believed or expressed. The references to clouds in AR4 pertain explicitly to positive feedbacks and climate sensitivity, i.e. given warming X from CO₂, how much additional warming Y will be added to that from clouds. AR4 (and scientists) are very upfront about admitting to this area of doubt in predictions, and adjusting error bars appropriately. But the admission is one of mere prudence and honesty, and part of the reason that the currently accepted range of climate sensitivity is between 2˚C and 4.5˚C per doubling of CO₂. Part of the reason for that wide range (2.5˚C total) is due to uncertainties about the effects of warming on clouds, and the corresponding effects of changed clouds on warming (although there are other factors, too).

Rob Painting at 08:05 AM on 3 November 2011

Richard Milne separates skepticism from denial
Shibui - watch Richard Milne's lecture - you're a textbook case of denial.

milka at 08:04 AM on 3 November 2011

Fred Singer Denies Global Warming
For the past forty years, Singer, Seitz and the rest of their small cabal of scientists - all deeply influenced by the Cold War - have waged war against any environmental problem that necessitated government action. Whether it was DDT, the harmful effects of smoking, anthropogenic acid rain, ozone depletion or global warming. Both Singer and Seitz pulled off their first major (-snip-) on the public by denying the link between cigarettes and lung cancer. From 1979 to 85 Seitz distributed $45million to scientists around the country on behalf of F. J. Reynolds Tobacco Co. The brief was to find other links to lung cancer other than cigarettes to get tobacco off the hook. Fred Singer co-authored a major report attacking the US Environmental Protection Agency over the health risks of second-hand smoke. Singer’s anti-EPA report was funded by an indirect grant by the Tobacco Institute. Using a tried and tested tactic successfully adopted by Big Carbon in the later global warming “debate”, the grant was channeled through an industry funded right-wing think tank, the Alexis de Tocqueville Institution. So successful was the (-snip-) played out on the public, so complicit was the mainstream media, so willing were the conservative politicians to forfeit policy decisions for hard cash that someone eventually came up with the bright idea of publishing the ultimate science bashing bible: ‘Bad Science: A Resource Book’ - a how to handbook with successful strategies to undermine science with a list of “so called” experts for hire whenever a negative sound bite was called for. No-one denies the link between tobacco and lung cancer anymore. Surely, Singer's credentials as a "go to" expert have been seriously undermined?

Response:

[DB] Inflammatory term snipped.

Bob Lacatena at 07:59 AM on 3 November 2011

Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
29, lancelot, 1) Smoothing over 60 years is inappropriate for this purpose, because the time span is too long. It's like putting on foggy sunglasses to fix a watch. You use smoothing to eliminate noise. In this case you would be using smoothing to eliminate the signal, too. 2) Solar activity does not equal sunspots. This needs clarification in three ways. First, no one denies that the sun is involved in climate (it is the continuous source of virtually all energy on earth, for crying out loud!). But the fact is that the variations in total solar irradiance (TSI) are very, very small, but obviously over long time spans it can be a factor. Other factors (such as GCRs) are being researched, but there are currently more reasons to doubt their involvement in current warming than to give it any weight. Second, sunspots are a proxy for total solar irradiance and other relevant factors (such as magnetic field strength). There is some correlation between sunspots and these values, and there are sunspot counts going back 400 years, so they serve as a proxy for those important values, while direct measurements only exist since the modern instrument era and space age. But sunspots themselves are nothing more than visible blemishes on the sun which signal changes in solar activity. Sunspots themselves are nothing from that point of view. They are the greening leaves that tell you the warmth of spring has arrived, but they are not the warmth of spring themselves. Third, climate models have been successful at identifying the causes of short-term climate change (volcanic activity, solar variations, etc.) throughout the recent climate record. Basically, we can account for the forcings (including the sun) for the length of that graph, and within that the forcing which is causing the warming in the past 30 years is CO₂. So to say that there has been constant warming since 1800 is misleading, because it implies that such warming is the result of one source, or some ongoing, mystical trend, when in fact there are periods of warming and cooling within that period, and more importantly the factors involved in each period of warming or cooling are known and quantified. There's no reason to think that they are all caused by something else, so CO₂ is therefore off the hook.

lancelot at 07:58 AM on 3 November 2011

Climate's changed before
Scaddemp: IPCC reports do mention cloud cover: AR4: "Significant uncertainties, in particular, are associated with the representation of clouds, and in the resulting cloud responses to climate change. " "Cloud feedbacks remain the largest source of uncertainty in climate sensitivity estimates." Not very definitive! Bob Lodlaw 129: That BSRN is really interesting work. Sadly I am not equipped to analyse the BSRN data, and I dont have access to the Wild 2009 paper right now. But I will keep looking into it and would like to come back to you on that subject. However my point was not really about 'bright sunshine' but about the net energy received at earth surface. Scaddenp 248: If it useful to know the energy actually received at earth surface, as a possible contribution to forcing, I cannot see point of measuring incoming solar irradiance by satellites at the exosphere, then making more satellite observations of 'cloudiness' to make an estimate how much actually gets through to earth surface,instead of simply measuring the actual energy received at the surface in the first place. That is in essence, and crudely, what sunshine hour records tend to do. It is not hard to measure the surface energy received per day - a PowerMonkey and a calorimeter I would imagine. I have not found data on surface energy receipts in the IPPC reports, other than the simplistic 'energy balance' diagrams. How do climatologists know the trends or variations of net energy received globally at the earth surface? How can you account for that or eliminate it as a possible forcing in models if you don't have the data? Tom Curtis, I take your point that England is not the world. Surely all the more reason to have a global measuring system such as BSNR. Sphaerica, you mention aerosols etc, but my point was about cloud forcing. Are you certain that there are no possible mechanisms driving cloud formation, other than those considered in AR4? GCR's may be out of the picture; I have mentioned micro-organisms a number of times in this forum, but the response has been a stony silence. Is that because readers are much too kind to lambast me for my stupidity in thinking that the airborne biosphere might(repeat might!) have a part to play in climate?

Response:

[DB] An open copy of Wild 2009 can be found here.

Mercury Scientist at 07:43 AM on 3 November 2011

Is there a case against human caused global warming in the peer-reviewed literature? Part 1
I recall a buzz about a questionable journal some years ago -- I think it was Energy and Environment, but cannot recall for sure. At the time, they claimed to have a process known as "super review" or "superreview" or something like that. I peeled back a layer, and I learned that "superreview" meant that if the author of the paper had ever published anything in the peer reviewed literature, then that was good enough, and the current manuscript under consideration did not need to be subject to the normal peer review process. So, "superreview" would better be called "no review," because that's what it was. With a few minutes on google today, I could not find anything about superreview and Energy & Environment. But, they have been taken to task a number of times for shoddy papers and questionable review practices. http://www.realclimate.org/index.php/archives/2011/02/ee-threatens-a-libel-suit/ http://www.realclimate.org/docs/thacker/skeptics.pdf

PhilMorris at 07:34 AM on 3 November 2011

Fred Singer Denies Global Warming
Fred Singer - one of the hero's in the book 'Merchants of Doubt'. Frankly I don't think anyone should take notice of anything he says, he as absolutely no credibility whatsoever.

Albatross at 07:28 AM on 3 November 2011

Richard Milne separates skepticism from denial
Hi Ian @57, SkS has dealt with Ridley's musings before. See here. In fact, AndyS did a whole series, that is how much misinformation there was to counter.

muoncounter at 07:26 AM on 3 November 2011

Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
lancelot#29: "total is a long term rise of about 0.9 deg C over 140 years." Or you could say a rise of 1 deg C in the 40 years since 1970. Surely you don't believe that a single straight line will fit the entire dataset from 1800 on?

Now that's a significant change in trend!

scaddenp at 07:21 AM on 3 November 2011

Richard Milne separates skepticism from denial
"I get the feeling some of you didn't like it ..." Some of us have a great respect for the truth.

lancelot at 07:04 AM on 3 November 2011

Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
27, 28: Nice to see the full graph at last! Well... I did say 'if smoothed'. Over 60 year periods, if smoothed on that basis the line is gradual (repeat gradual) and fairly (repeat fairly) uniform. I have done that on paper, that is how it looks. The total is a long term rise of about 0.9 deg C over 140 years. Tom Curtis - I totally agree however with your more detailed analysis. A rise 1800-50. A flat period 1850-1910. Then a sharp rise 1910-40. That actually illustrates my point. If you start the chart at 1850, you see a flat period until the start of the 20th century, then a prominent rise. So it looks as if warming started in 1910. It didn't. It started at least before 1800. Sphaerica: It is clear (even to a non-climatologist) that volcanic eruptions and solar irradiance variation will cause the visible intermediate ups and downs within the longer time scales. In that context you also referred to the Dalton minimum and 'solar activity', i.e. sunspots. Does that mean that you consider sunspots to be associated with forcing or with climate changes in general?

Ian Forrester at 05:39 AM on 3 November 2011

Richard Milne separates skepticism from denial
Matt Ridley is on the Academic Advisory Council of The Global Warming Policy Foundation alongside such well known AGW deniers as Ian Plimer, Richard Lindzen, Robert Carter, Ross McKitrick, William Harper and many others. As such, anything he says is not based on science but on his libertarian ideology. As an aside he was Chairman of Northern Rock the first Bank to face problems in the UK, problems which appear to be blamed on Matt Ridley.

muoncounter at 05:10 AM on 3 November 2011

Sorting out Settled Science from Remaining Uncertainties
CBD#31: "the claim that it is minor compared to internal variability." It would be interesting to see the evidence for this cart-before-horse argument, if any exists. Here, on the other hand, is a demonstration that there is an ongoing warming trend with short-term variability written on top of that trend.

- source The red is BEST with a 12 month mean; green is the linear trend. Then use the detrend operator to remove that, yielding the blue curve. That can be described as short period, with a constrained amplitude and oscillation around 0; if this was an electronic signal, it sure looks like noise ~~short-term internal variability~~ to me. Of course, tamino did this with greater sophistication last year. Has anyone in deniersville produced a graph like this showing that internal variability swamps the trend or are we supposed to just take their word for it?

MewCat100 at 04:58 AM on 3 November 2011

CO2 measurements are suspect
Probably no one is reading this blog any longer, but the answer should be as follows. 1. The atmosphere thins as we move upward due to gravity. 2. The partial pressure of oxygen is always about 0.21 3. Because there is less gas at high altitudes than low altitudes, there is less TOTAL oxygen at those levels, but it is still 21 percent of total. So if there are 1000 gas molecules at surface, 210 are oxygen. At high altitudes, say the total is 100, then oxygen is 21. 4. From this it follows that CO2 is not evenly distributed on vertical basis in the atmosphere. Consequently, this also applies to temperature given that there are thremoclines in the vertical expanse of the atmosphere. 5. CO2 total is different from one altitude to the next, but CO2 percentage (of total atmospheric gas) should be consistent.

wingding at 03:12 AM on 3 November 2011

Fred Singer Denies Global Warming
Re 18,19 I concur. Muller's results vindicated Hansen and Jones from years of denier accusations of cooking the books, deleting stations, rewriting history, exaggerating warming, etc. All of which DO constitute denying global warming. The deniers have played a sleight of hand by claiming they always accepted the world warmed. That's not the point. The point was that they were denying global warming had played out as shown in HadCRUT and GISTEMP. The deniers are mad because Muller went public about them being wrong. Effectively they've been held accountable for their false claims and they don't like it one bit.

pbjamm at 02:35 AM on 3 November 2011

Fred Singer Denies Global Warming
Shoyemore@18 Muller's statements undermined a key myth of denialism - that "the books are cooked" ^^^^^ THIS is the reason that the 'skeptics' can not accept the BEST data. If Muller/BEST agree with the crooks then he too must be a crook. Reference Steve L's point one.

dana1981 at 02:28 AM on 3 November 2011

Sorting out Settled Science from Remaining Uncertainties
daisym, aside from echoing the previous suggestions that you use our site's search tool to find the answers to your questions, I would also like to point you to some text in the post above which you seem to have missed:

"The short-term effects can only temporarily dampen (or amplify) that long-term man-made global warming trend."

DSL at 02:11 AM on 3 November 2011

Richard Milne separates skepticism from denial
What did you take from Ridley, Shibui? Did he convince you of anything?

Climate Science Glossary

Term Lookup

Settings

Term Lookup

Settings

Latest Posts

Recent Comments

Planting Trees Won't Help