National Geographic News
Photo of cumulus clouds against a blue sky.

The mixing of clouds—like these cumulus clouds—is setting the globe on a path to warmer temperatures, scientists say.

Photograph by incamerastock/Alamy

Dan Vergano

National Geographic

Published December 31, 2013

A decline in ocean cloud cover projected in climate models points to more than 5.6°F (3°C) of global warming coming in this century, on the high end of past global warming estimates, warn climate scientists in a new study. (See also: "Global Warming Effects Map.")

"This degree of warming would make large swaths of the tropics uninhabitable by humans and cause most forests at low and middle latitudes to change to something else," says Steven Sherwood of Australia's University of New South Wales, who led the study.

The changes, Sherwood says, would take Earth "back to the climate of the dinosaurs or worse, and in a geologically minuscule period of time—less than the lifetime of a single tree."

Atmospheric scientists have long asked how high atmospheric temperatures will rise if greenhouse gases double. This "climate sensitivity" estimate has emerged as a key climate question, with estimates ranging from a low of about 2.7°F (1.5°C) to highs of more than 8°F (4.5°C) of warming in this century.

While estimates have gone up and down, carbon dioxide concentrations have increased to a level about 40 percent higher than the preindustrial average in the last century, largely due to the burning of fossil fuels.

In a new analysis released by the journal Nature, an international research team led by Sherwood reports that better cloud-cover physics narrow the spread of disagreement among the climate sensitivity estimates.

Cloud Cover Cook-Off

In the study, the researchers looked at ocean clouds, which at low altitudes reflect sunlight and lead to cooler global temperatures. The Nature study suggests that global warming will mix growing amounts of higher, drier air with ocean clouds over the course of the century, thinning out the clouds and reducing their cooling effect.

"It is an elegant and important paper," says Penn State climate scientist Michael Mann.

The finding matters, he adds, because a 2013 Intergovernmental Panel on Climate Change (IPCC) report had widened its range of climate sensitivity estimates to embrace the low estimates for how high temperatures will rise by the year 2100. (See also: "Global Warming Report: 5 Big Takeaways.")

"I argued that the IPCC had erred," Mann says, based on historical climate patterns. Sherwood and his colleagues, he says, "provide a rigorous physical explanation of just why."

Climate Sensitivity Settled?

"So can we declare the long-running debate about climate sensitivity to be over?" say climate scientists Hideo Shiogama and Tomoo Ogura of Japan's National Institute for Environmental Studies, in a commentary accompanying the study.

"Unfortunately not," they conclude. "Sherwood and colleagues' study represents a big advance, but questions persist."

For one thing, better estimates of ocean cloud cover explain only about half of the variation in climate sensitivity estimates. Uncertainty over the cooling effects of ice cover and clouds over the continents remain.

But Mann argues that the paper adds to growing concerns about the "uncertainty" in climate change science being more bad than good for humanity: "We should be taking into account worst-case scenarios when we attempt to gauge the risks posed by climate change."

Follow Dan Vergano on Twitter.

64 comments
David Norminton
David Norminton

I thought I'd reply to Linda Glass' statement someway below where she stated  "Michael Mann was investigated no less than 8 times, and every single person found him to be innocent of ANY wrong doing." I'll then go onto more general matters.


Linda's statement is incorrect. Michael Mann and his hockey-stick methodology was found wanting by Edward J Wegnman some years ago in his report to the Committee on Energy and Commerce (in the USA). This criticism was echoed (although using much more conciliatory language) in another report by North. Pressed later on the matter, North stated "We don’t disagree with their [Wegman's] criticism. In fact, pretty much the same thing is said in our report." These criticisms were bizarrely reported in the media as an exoneration of Mann's methods and therefore his hockey-stick findings. To this day, those on the AGW side of the argument still insist that there is nothing wrong with Mann and his hockey-stick representation of the last 1,000 year temperature record, and often cite so called independent papers by Mann's serial co-authors Wahl and Ammann as evidence of that, but those papers turned out to be flawed in much the same way (by using many of the same discredited proxies and statistical techniques for example).


The point here is that Mann's reputation among many both within and outside of the scientific community is very low. His shenanigans over disclosing his data, methodology and computer codes (over many years) so that his findings could not be reproduced was (and still is) a disgrace. I suspect that even some on his own side are embarrassed by him, but he continues to be feted by the media, including, so it seems, the National Geographic. Indeed, it seems that Mann's disregard for the scientific method (that all results should be reproducible) seems fairly widespread within the paleoclimatalogical community, often hiding behind intellectual property arguments, even where they, or the data they use, has been publicly funded. I find it really odd that so many pro AGW climatologists find this acceptable.    


As for the quality of the scientific debate regarding AGW, it is sadly lacking. Vast amounts of money are being spent on the premise that the science is settled, whilst at the same time, very few, if any of the vast number of peer reviewed papers that aren't useful to the AGW viewpoint are discussed by the media, or I suspect by many of those posting here. The truth is, the IPCC 5 yearly reports are not balanced, or at least as balanced as they should be. By their own criteria, they by and large exist to assess the case for anthroprogenic global warming (AGW), and are therefore much less interested in peer reviewed scientific papers that provide alternative explanations. All the IPCC do is collate the "evidence for" and they don't check it's scientific validity. Many of the lead authors of the various chapters are from a relatively small AGW community, and so they naturally tend to cite their own papers and those of their colleagues that have published supportive papers.  For a more balanced review, you need to go to the NIPCC website, where they present a much more balanced view taking into account the vast amount of scientific literature on BOTH sides of the argument. It makes extremely interesting reading and is thoroughly referenced throughout.


Of course, I fully understand that many reading my post will be dyed-in-the-wool AGW believers, much more content with visiting websites that reinforce their own beliefs (such as Michael Mann's RealClimate website), than genuinely making an effort to seek out  more balanced views. I judge no-one for that. But I still think exposure to some of the counter arguments would be very worth while for many, even if it does't change minds.


For my own part, I believe that the global warming that has taken place in the last 200 years (and of course before that!) has been due in large part to natural cyclical changes in climate following what is now thought to have been the coldest spell in the last 5,000 years - the little ice age. Clearly, some of the more recent temperature increases can be attributed to CO2, because everyone (surely by now!) accepts that CO2 is a greehouse gas. But the contribution to this more recent increase (between about 1978 and 1998) is, for reasons given elsewhere in this thread, necessarily fairly tiny. All the observed changes in sea level (isostatic changes aside), glacier retreat, and changes in minimum arctic ice coverage are a direct result of this continuing temperature adjustment. They are not (as is commonly believed by many who have only a tenuous grasp of the issues) proof of the anthroprogenic part of AGW. 


The real area of disagreement between sceptics and believers in catastrophic AGW (CAGW) is Climate Sensitivity, the amount that average global temperature will increase in response to a doubling in atmospheric CO2. Without any feedback mechanism in operation, climate sensitivity is around 1.0 to 1.2 degrees C.  But those who believe in CAGW think that positive feedbacks will increase global temperatures by several more degrees and a tipping point will be reached meaning global temperatures will race away catastrophically. Sceptics by and large however, believe that the evidence for this scenario is wholly inadequate, and is likely to be wrong. And there you have the AGW debate in a nutshell. The fact is that no-one really knows exactly which feedback mechanisms operate , and how they interact with each other. Climate models all contain the assumption that any feedback that occurs will be positive, but this is by far the most controversial and least understood aspect of climate science. For my own part, I look back at the temperature record over geological history and note that increased global temperatures have always preceded increasing CO2 levels (by several hundred years on average). This implies that temperature increases in the past have been caused by natural climate variables that have then acted to expell CO2 from the oceans etc. But more importantly (and probably more relevantly) I've seen no evidence of positive feedbacks causing run-away global warming either. There have been times in geological history where CO2 concentrations have been far higher than today, with comparable global temperatures to today's. This implies to me that negative feedbacks are also important and act to dampen (and likely reverse) any positive feedbacks. Don't forget that as CO2 increases, it's ability to act as a greenhouse gas diminishes.  


Lastly, I am disappointed to note some on here using the term "denier" to disparage those holding a counter view. It's a pretty childish way to dismiss those you don't agree with, and to some, offensive. I'm not even sure what us skeptics are supposed to be denying? If two sides disagree about a part of science that is still very much in its infancy and far from settled (as per above) then how could either party be said to be denying anything? It's an irrational statement to make and I suggest we all get a grip and discuss the science and leave the silly name calling alone. 


Roxanne Roxanadanna
Roxanne Roxanadanna

Volcanic eruptions, like Mount Pinatubo, decrease planetary temperatures. Would it be possible to intentionally cause volcanic eruptions in places lacking people to end global warming?  One could presumably do this every two years if needed.

Parikshit Prasad
Parikshit Prasad

This change in the sea temperatures is going to be devastating as it might change the entire life of the coral population throughout the oceans of the world..

m s
m s

the climate is already changing, the town i grew up in 40 years ago was humid and hot all year round, now it's mild, cold and muggy and has 2 distinct seasons. It's happening already but people will continue to deny it until it's too late.

Harold Seneker
Harold Seneker

The real issue here is Anthropogenic Global Warming, and in particular anthropogenic carbon dioxide emissions. Here are some crucial, verifiable and authenticated facts about that people need to know and seem not to know:



The fact is, there has been global warming, but the contribution of human-generated carbon dioxide is necessarily so minuscule as to be nearly undetectable. Here's why:

Carbon dioxide, considered the main vector for human-caused global warming, is some 0.038% of the atmosphere[1]- a trace gas. Water vapor varies from 0% to 4%[2], and should easily average 1% or more[3] near the Earth’s surface, where the greenhouse effect would be most important, and is about three times more effective[4] a greenhouse gas than carbon dioxide. So water vapor is at least 25 times more prevalent and three times more effective; that makes it at least 75 times more important to the greenhouse effect than carbon dioxide[5]. The TOTAL contribution of carbon dioxide to the greenhouse effect is therefore 0.013 or less. The total human contribution to atmospheric carbon dioxide since the start of the industrial revolution has been estimated at about 25%[6]. So humans’ carbon dioxide  greenhouse effect is a quarter of 0.013, works out to about 0.00325. Total warming of the Earth by the greenhouse effect is widely accepted as about 33 degrees Centigrade or 59 degrees Fahrenheit. So the contribution of anthropogenic carbon dioxide is less than 0.2 degrees Fahrenheit, or under 0.1 degree Centigrade. Global warming over the last century is thought by many to be about 0.6 degrees Centigrade.


But that's only the beginning. We've had global warming for more than 10,000 years, since the end of the last Ice Age[7]. Whatever caused that, it was not human activity. It was not all those power plants and factories and SUVs being operated by Stone Age cavemen while chipping arrowheads out of bits of flint. Whatever the cause was, it melted the glaciers that in North America once extended south to Long Island and parts of New York City[8] into virtually complete disappearance (except for a few mountain remnants). That's one big greenhouse effect! If we are still having global warming - and I suppose we should presume we are, given a 10,000 year trend - it seems highly likely that it is still the overwhelmingly primary cause of continued warming, rather than our piddling 0.00325 contribution to the greenhouse effect.


Yet even that trend-continuation needs to be proved. Evidence is that the Medieval Warm Period centered on the 1200s was somewhat warmer than we are now[9], and the climate was clearly colder in the Little Ice Age in the 1600s than it is now[10]. So we are within the range of normal up-and-down fluctuations without human greenhouse contributions that could be significant, or even measurable.


The principal scientists arguing for human-caused global warming have been demonstrably disingenuous[11], and now you can see why. They have proved they should not be trusted. 


The idea that we should be spending hundreds of billions of dollars and hamstringing the economy of the entire world to reduce carbon dioxide emissions is beyond ludicrous in light of the facts above; it is insane. Furthermore, it sucks attention and resources from seeking the other sources of warming and from coping with climate change and its effects in realistic ways.The true motivation underlying the global warming movement is almost certainly ideological and political in nature, and I predict that Anthropomorphic Global Warming, as currently presented, will go down as the greatest fraud of all time. It makes Ponzi and Madoff look like pikers by comparison.



[1] Fundamentals of Physical Geography, 2nd Edition
by Michael Pidwirny
Concentration varies slightly with the growing season in the northern hemisphere.  HYPERLINK "http://www.physicalgeography.net/fundamentals/7a.html" http://www.physicalgeography.net/fundamentals/7a.html

[2] ibid.

[3] HALOE v2.0 Upper Tropospheric Water Vapor Climatology Claudette Ojo, Hampton University; et al..  HYPERLINK "http://vsgc.odu.edu/src/Conf09/UnderGrad%20Papers/Ojo%20-%20Paper.pdf" http://vsgc.odu.edu/src/Conf09/UnderGrad%20Papers/Ojo%20-%20Paper.pdf. See p. 4.The 0 - 4% range is widely accepted among most sources. This source is listed for its good discussion of the phenomena determining that range. An examination of a globe will show that tropical oceans (near high end of range) are far more extensive than the sum of the earth’s arctic and antarctic regions and tropical-zone deserts (all near the low end). Temperate zone oceans are far more extensive than temperate-zone desert.  This author’s guess of an average of 2% or more seems plausible. I have used “1% or more” in an effort to err on the side of understatement. 

[4 NIST Chemistry Webbook, Please compare the IR absorption spectra of water and carbon dioxide. ]  HYPERLINK "http://webbook.nist.gov/" http://webbook.nist.gov/

[5] Three quarters of the atmosphere and virtually all water vapor are in the troposphere. Including all the atmosphere would change the ratios to about 20 times more prevalent and 60 times more effective. However, the greenhouse effect of high-altitude carbon dioxide on lower-altitude weather and the earth’s surface seems likely to be small if not nil.

[6] National Oceanographic and Atmospheric Administration.  HYPERLINK "http://www.ncdc.noaa.gov/oa/climate/gases.html" http://www.ncdc.noaa.gov/oa/climate/gases.html. The estimated 90ppm increase in carbon dioxide, 30% above the base of 280  ppm, to a recent reading of 370 ppm, equates to just under 25% of present concentration, the relevant factor in estimating present contribution to the greenhouse effect.

[7] Oak Ridge National Laboratory http://www.esd.ornl.gov/projects/qen/nerc130k.html

[8] New York Nature - The nature and natural history of the New York City region. Betsy McCully http://www.newyorknature.net/IceAge.html

[9]Global Warming: A Geological Perspective John P. Bluemle HYPERLINK "https://www.dmr.nd.gov/ndgs/Newsletter/NL99W/PDF/globlwrmw99.pdf" https://www.dmr.nd.gov/ndgs/Newsletter/NL99W/PDF/globlwrmw99.pdf This article, published by the National Oceanographic and Atmospheric Agency, is drawn from a paper by the author in Environmental Geosciences, 1999, Volume 6, Number 2, pp. 63-75. Note particularly the chart on p.4.

[10] Ibid.

[11] Wikileaks: Climatic Research Unit emails, data, models, 1996-2009  HYPERLINK "http://wikileaks.org/wiki/Climatic_Research_Unit_emails,_data,_models,_1996-2009" http://wikileaks.org/wiki/Climatic_Research_Unit_emails,_data,_models,_1996-2009

See also  HYPERLINK "http://www.dailymail.co.uk/news/article-1246661/New-scandal-Climate-Gate-scientists-accused-hiding-data-global-warming-sceptics.html" http://www.dailymail.co.uk/news/article-1246661/New-scandal-Climate-Gate-scientists-accused-hiding-data-global-warming-sceptics.html and

HYPERLINK "http://online.wsj.com/article/SB10001424052748704075604575356611173414140.html" http://online.wsj.com/article/SB10001424052748704075604575356611173414140.html and, more diplomatically:  HYPERLINK "http://www.nytimes.com/2009/12/01/science/01tier.html" http://www.nytimes.com/2009/12/01/science/01tier.html. Et al.

Craig Miller ッ
Craig Miller ッ

We can change the global climate, but we are thinking the wrong way. Instead of all of these studies trying to prove climate change is linked to industrialization, those scientists should be working more with other scientists to figure out the best way to counter the issue. Also, whether we are causing change or not, we should welcome "green" ideas and become more sustainable. By the time we all agree that climate change is happening, it will be too late to reverse the effects. So, reducing emmissions and becoming more sustainable should be a top priority for governments of the world when it comes to the need for more energy.

Harold Seneker
Harold Seneker

The error lies in treating models as if they are fact. They are not. They are merely complicated hypotheses unless and until their predictions are tested and found to be correct. 


Anyone who haas worked with even very simple models knows how easy it is to tweak them to produce almost any result you want. Small changes in a few factors that have numerators and denominators can cumulatively add up to enormous variation in end results. Start playing with exponents, logs, and calculus, and maybe throw in an assumption or two that is wrong no matter what maths you apply, and the possibilities for bad predictions can become virtually infinite.


There have been a lot of climate change models, and so far none of them have succeeded in making predictions that prove out. None. 


Even failed models can be useful for further inquiry - the nature of their failure can point to the underlying assumptions that need to be corrected, changed or deleted. But until they make predictions that prove out they are worse than useless as a basis for formulating policy, because they can delude people into false confidence that what they are planning to do is in fact the correct thing to do.


So here is another hypothesis that fits the global warmists' agenda. 

Jeffery Green
Jeffery Green

http://www.scilogs.de/klimalounge/files/MRIscenario1.png

http://www.realclimate.org/index.php/archives/2013/12/the-global-temperature-jigsaw/


Figure 2 Temperature evolution in a model simulation with the MRI model. Other models also show comparable “hiatuses” due to natural climate variability. This is one of the standard simulations carried out within the framework of CMIP3 for the IPCC 2007 report. Graph: Roger Jones.


####################


These really flat assumptions put out as fact are interesting. Here is a model showing a 21 year hiatus and projecting more into the future. Notice that we rise about 3.5*C by 2100.

Harold Seneker
Harold Seneker

The error here is treating the predictions of models as if they were fact. They are not. They are only the product of the assumptions built into the models. Models are only useful as predictors AFTER the predictions they make have been found to be accurate and reliable. This is how science works: you advance a hypothesis, then look at the real world to see if the predictions the hypothesis makes turn out to be true.


This testing step is essential. Anyone who has worked with even very simple models can tell you how easy it is to tweak a model to produce almost any answer you want. If a model contains several factors with numerators and denominators, small inaccuracies in them cumulatively can add up to big changes in end results. And that's at the high school level. Start playing with exponents, logs and formulae incorporating calculus and this problem is greatly magnified. Add in even one, or more likely a few, assumptions that are conceptually incorrect no matter what math you use, and you quickly find yourself dealing in nonsense.


There have been many such climate models and none of them predicted the behavior of climate over the last 17 years. None. 


They may still be useful - when a model's predictions prove wrong, the discrepancy can give you clues about what assumptions are incorrect. But until they have proved themselves by making predictions that actually come true, they are only speculation and as such useless, and potentially even dangerous, as guides to policy. And if the predictions they make are in fact shown to be wrong - as is happening as we speak - it is very likely that using them as guides to policy will be counterproductive.


T Ken
T Ken

Climate Sensitivity Settled?

Only a fool or charlatan would suggest this given the multi variate nature of the climate system.

Guy Holder
Guy Holder

These articles continue to get more desperate and alarming the longer we go without warming. After a 17 year "pause" it's clear our co2 emissions are not the primary driver of climate. 

Obviously the timing of this article is meant to divert attention from the Akademik Shokalskiy, trapped in summer ice in the Antarctic.

Dan Libby
Dan Libby

I don't bother with people who deny science. I'm mildly surprised to find them on sites devoted to knowledge but then reflect on how much they enjoy being ignorant contrarians. So I repeat to myself this saying, "Never try to teach a pig to sing; it wastes your time and it annoys the pig."

Chris Wiegard
Chris Wiegard

Carl, deniers are everywhere on the web. they tend to congregate on sites such as this one because they have a perverse urge to stand in he way of actual discussion of climatology. their actual numbers in the US population are not large, but they are pretty willing to spend every waking moment trying to give the false impression that they are a majority.

one tends to recognize them fairly easily because for them, animus rules all. it's not about the science, it is about Al Gore or Michael Mann being truly evil people who struggle to destroy capitalism in order to make a few bucks.

Carl von Kleist
Carl von Kleist

Wow, I'm surprised to see so many completely uninformed people in complete denial of modern science on the National Geographic website.

Dwayne LaGrou
Dwayne LaGrou

Why don't they collect the carbon dioxide comming out of a coal burning power plant and inject it into one of these coal mine fires that have been burning for decades to try and extinguish it with the very stuff they are emitting into the atmosphere. It seems to me that the CO2 that the fires would be emitting for another half a century would be a huge contribution to global warming. It would basically kill two birds with one stone! Any comments?

Peter S.
Peter S.

Speculative article that provides little value. The focus seems to be on Mann's comments not the science and the physics behind the theory.


Explain the science behind the following:

"TheNature study suggests that global warming will mix growing amounts of higher, drier air with ocean clouds over the course of the century, thinning out the clouds and reducing their cooling effect."


As a tropical meteorologist for three plus decades, I find that such conjecture is pure speculation and shows a superficial and limited understanding of atmospheric thermodynamics, cloud micro-physics, fluid dynamics and more recently cloud nucleation mechanisms resulting from cosmic particles in the atmosphere.


Modern meteorology is undergoing a long overdue evolution (it's been slow, I'd rather it were a revolution), with research that is embracing modern physics. Specifically quantum mechanics, solar physics and particle physics. Unfortunately all climate models are clueless about such processes and there is a lot more to the atmospheric processes than just CO2. 


http://arxiv.org/pdf/0707.1161v4.pdf


http://home.web.cern.ch/about/updates/2013/10/cows-clouds-and-climate


As Richard Feynman stated:

"It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."


In the interests of creating scientifically literate humans, we need to increase our  fundamental scientific understanding and stop the speculation. This will take  tenacity,  diligence and integrity.

Dan Vergano
Dan Vergano

@David Norminton There is a great deal wrong with the conflation of the 2006 Wegman report with the post-2009 investigations exonerating Mann and his colleagues from ethics charges after the theft of emails from the University of East Anglia. First, the two things don't have anything to do with each other, as the dates mentioned should make obvious. One was about statistics in a 1999 paper (since replicated a dozen or so times) and the other was about ethics charges in 2009. All of those were found without merit. It is dishonest to conflate these exonerations with the assertions made in the Wegman report.


Second the Wegman report has been shown to have numerous problems, including plagiarism, inadequate peer-review, poor data and other problems well noted by Columbia University statistician Andrew Gelman. Wegman's university censured him for plagiarism as a result. The portion of his report that made it into a peer-reviewed journal was retracted as a result of its ethical shortcomings. It is remarkable that anyone so interested in climate science ethics can somehow fail to know this.


Michael Mann continues to be a well-respected figure in climate science: He chaired the 2012 American Geophysical Union meeting session on climate sensitivity (where he gave a standing room keynote speech as well), and has published twice in peer-reviewed journals on the topic in peer-reviewed journals in the last year. That is why he was asked to comment on this story. It is simply dishonest to regard him as other than a well-qualified climate scientist.


There was a call to discuss the science in this note -- that requires honesty.

Bart Hoekstra
Bart Hoekstra

@David Norminton First of all, the science does not say we will have a run-away climate. The effect of positive feedbacks diminishes over time.


Some comments and questions in bold.

“There have been times in geological history where CO2 concentrations have been far higher than today, with comparable global temperatures to today's.” - So what about solar and geological activity in those same periods?


“For my own part, I look back at the temperature record over geological history and note that increased global temperatures have always preceded increasing CO2 levels (by several hundred years on average).” - Tell me, how do you look back at these records of temperature and CO2 levels, without using the same proxies Michael Mann uses, that you so firmly call ‘discredited’? What proxies do you use then…?

And regarding use of the term ‘denier’: There is a difference between deniers and skeptics. Skeptics are rationally skeptical about something, deniers aren't rational. That's the difference. In this comment thread the deniers are mainly saying ‘it's not warming’, which obviously is not the skeptics opinion (as you point out so nicely).

John Patt
John Patt

@Harold Seneker  The idea that we should be spending hundreds of billions of dollars and hamstringing the economy of the entire world to reduce carbon dioxide emissions is beyond ludicrous in light of the facts above; it is insane.


You are correct that this is an economic issue. People and businesses all over the world are going to move into solar and other alternative forms of energy. We are all going to save huge sums. The fossil fuel industry sees this, rightly, as competition, and will do whatever they can to stop it. By attacking global warming, they are trying to discredit the competition. 

m s
m s

@Harold Seneker That's like claiming that global warming has increased naturally because the sun rises everyday, it's a strawman and posting links to these types of ridiculous claims that it's not increased dramatically because of our activity doesn't make your argument anymore true.

Roxanne Roxanadanna
Roxanne Roxanadanna

@Craig Miller ッ Perhaps all buildings should have white roofs.  There would then be more reflection of heat back into space, with a very modest mitigation of global warmings.

Jean B.
Jean B.

@Craig Miller ッ Besides, it makes economic sense.  We got a 96% efficient furnace and AC. Gas usage has been halved.  Looking forward to the summer savings. Governments will soon see the light and heat their buildings and schools with solar.

Roxanne Roxanadanna
Roxanne Roxanadanna

@Harold SenekerModels are but one element in an analysis of complex events.  What you need to do to show this whole thing is fraudulent, however, is to deny 1) the measurements of temperature by satellite, showing increases every year, & 2) explain how glaciers retreat. You can find many other examples, but this one is fun because you get to watch the glacier shrink by pushing the buttons. http://earthobservatory.nasa.gov/Features/WorldOfChange/columbia_glacier.php


Glaciers all over the earth are shrinking. Water freezes at 0 C. The higher the altitude the lower the temperature.  How apart from increasing warmth can the retreat of glaciers to higher altitudes be explained?

Bart Hoekstra
Bart Hoekstra

@Harold Seneker Semantically speaking models don't do predictions, they create projections. The researchers are describing projections in their paper (and so is this article) and no predictions, so I don't know what your comment has to do with the article.

To cite the IPCC:
A climate projection is usually a statement about the likelihood that something will happen several decades to centuries in the future if certain influential conditions develop. In contrast to a prediction, a projection specifically allows for significant changes in the set of boundary conditions, such as an increase in greenhouse gases, which might influence the future climate. As a result, what emerge are conditional expectations (if this happens, then that is what is expected). For projections extending well out into the future, scenarios are developed of what could happen given various assumptions and judgments.” - http://www.wmo.int/pages/themes/climate/climate_projections.php


And if I replace the ‘predictions’ in your comment by ‘projections’, you're wrong about the fact that the trends we're observing aren't in the climate models. They are.

That is because climate models are tested against the past climate and improved as we know more about the workings of our climate. If they manage to match their projections of the past climate with the actual observed climate there is no reason that future projections will be wrong.

Cameron Spitzer
Cameron Spitzer

@Harold Seneker, I've used numerical models of thermodynamics, circuits, and transmission lines.  They were always complex enough to set up that by the time I was getting useful results out of them they had shown me their most obvious limits.  My measurement tools were the same way.  Calibrating an instrument sometimes means making a model of how the instrument works.  Read the so-called "climategate" files some time.  Not the little snippets broadcast on right wing talk radio, but the original unedited email threads.  There's some gossip, but mostly they discuss experience with models and instruments, along the same lines as mine but vastly more complex.  You learn how tools work, and what they can and can't do, by experimenting with them.


Which brings to mind that "no warming for 17 years" thing, sometimes expressed as "none of the models predicted that."  Climate models describe decades- and centuries-long phenomena.  Looking for a 15-year blip in their output seems rather like trying to measure the voltage on a flashlight cell with a kilovolt meter, and then declaring that voltmeters "don't work."

John Patt
John Patt

@Harold Seneker Are you saying that we cannot accept global warming as fact until it (and the attendant catastrophes) are in place? 

Cameron Spitzer
Cameron Spitzer

@Jeffery GreenThe realclimate piece effectively refutes the "no warming for 17 years" misrepresentation.  Bookmarked.  Thanks!

Jack Wolf
Jack Wolf

@Harold Seneker You need to open your eyes and look outside.  Physical evidence abounds whether it's the moving vegetation communities to the shear number of big weather event, not to mention ice loss, sea level rise, increases in precipitation amounts.  Everything is happening as expected in a warm world, but yet you say otherwise.


So, I find it hard to believe that your comments are even remotely relevant to the discussion at hand.

Cameron Spitzer
Cameron Spitzer

@Harold Seneker,  Climate models aren't *supposed* to predict 17 year events.  Events of such short duration are expected to be lost in the noise of weather and random variability.  "No warming for 17 years" is emotionally compelling to someone looking for an excuse to deny the findings of a hundred years of climate related science, but it's nonsense.  We'll have a signal that by some miracle "the warming stopped" 17 years ago if global average temperatures still haven't moved 15 years from now.

Jack Wolf
Jack Wolf

@T Ken See, you didn't even read the article - that or you comprehension is muddled from last night still.  The piece clearly pointed out that the clouds only account for 50% of the unknowns and that questions remain.  But, much has been answered by this study, and it's not looking good. 

Bart Hoekstra
Bart Hoekstra

@Guy HolderThere is no ‘pause’ and there is not a single climate scientist that would argue CO2 is a primary ‘driver of climate’ (?).


Also, there is a difference between weather and climate. And there is a difference between trends and events. Models are about trends, not events.

Bart Hoekstra
Bart Hoekstra

@Dan LibbyI did agree with you for a long time, but I also feel a certain obligation to tell the actual story. So that people with little to no scientific background on these topics don't only come in contact with the denialist perspective on things.

Roxanne Roxanadanna
Roxanne Roxanadanna

@Chris WiegardNotice that when they are confronted with facts, the climate denialists tend not to reply.  Truth be told, the impression for me was that they WERE the majority of people on the planet!

Jim Satterfield
Jim Satterfield

@Mike Smithy The official Russian government position has been to deny the existence of global warming for years. And, BTW, The Daily Mail is a British tabloid with all of the credibility of the National Enquirer.

Cameron Spitzer
Cameron Spitzer

@Mike Smithy Both of Mike's links are opinion pieces from the anti-science smear campaign.  There's sociology research about that public relations project from Dr. Brulle at Drexel.  Brulle confirms last year's investigative reporting by the Independent and the Guardian.  The major finding is the oil companies that used to fund the project are anonymising their contributions now.

The dailymail is the paper that published David Rose's infamous "no warming for 15 years" lie, that was so effective the science deniers are *still* reciting it two years later.  That particular lie was so blatant the agency Rose misquoted disclaimed it the next day.

Jeffery Green
Jeffery Green

@Mike Smithy


Are you a denier? CO2 will cause to the earth to warm. Outstanding amounts of data show this to be true.

Andrew Booth
Andrew Booth

@Dwayne LaGrouHow would you collect the CO2 Dwayne? Hundreds of thousands of pressurised cylinders or tankers? Then how do you transport the gas to the site in sufficient quantity and then deliver it in the necessary quantity to extinguish the fire? That's just for one fire! Also, who do you propose pays for the costs of all the equipment and transport? Politicians won't be interested, nor will the tax payer.  

Jim Satterfield
Jim Satterfield

@Peter S. Meteorology != climatology. The CLOUD experiment at CERN is valuable science but still does nothing to disprove existing climate models.

John Patt
John Patt

@Peter S.  As Richard Feynman stated:

"It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong."


The same is true of global climate change denials. If you are wrong, we are going to have famines and wars of proportions the Biblical authors could only have imagined.

David Norminton
David Norminton


@Bart Hoekstra @David Norminton


Thanks for your post Bart and I concede your first point.


With regard to your first question, I agree that solar and geological activity will have had a part to play, and could help to explain the anomalies (which is what I assume you were getting at with the question?). But to what extent I do not know.


In answer to your second question, it was ice-core proxies I was referring to. For what it's worth, I don't think that tree-rings are a very good proxy for temperature, and there is of course the divergence between tree-ring widths and temperature in the last few decades that no-one really knows how to explain. 


There are many other types of  temperature proxy described in the peer-reviewed literature that indicate a pronounced medieval warming period (MWP) and little ice age (LIA). These studies come from various parts of the world (there are a surprising number of them if you search), and some show similar cycles going back even further in time. This clearly shows to me that the MWP and LIA were global phenomenon and not, as some believe, merely regional. This is important because those who seek to show that the temperature rise between 1978 and 1998 was unprecedented in the last 1000 years like to do that by smoothing out the temperature fluctuations during that period and splicing-on the real temperature record at the end to give a hockey-stick shape. Some controversial tree ring proxies are very useful for producing the "shaft" of the hockey-stick, and that's why they seem to be recycled in so many temperature reconstructions by Mann and his colleagues, despite their use being criticized by Wegman and North all those years ago.


Some also say the rate of temperature increase in the 20 year period between 1978 and 1998 is unprecedented, but I don't see that in the temperature record either. 


Unfortunately, the distinction you make between "denier" and skeptic is overwhelmingly ignored by the media and many AGW enthusiasts/scientists. Skeptics vastly outnumber those who don't believe that CO2 is a greenhouse gas, or that average temperatures have been increasing since the 18th Century. This tactic is just part of a dirty tricks campaign to stifle debate, and if the science was so certain (95% confidence level according to the IPCC!) then why the need to employ such methods? I'd love to know where this tactic came from and whether it was spontaneous or the result of some 'policy meeting' somewhere. It smells of the latter to me.     


Harold Seneker
Harold Seneker

@m s @Harold Seneker It is evident, m s, that you have not looked at the links I provided, which link to standard textbooks I chose because global warmists have cited them, standard databases depended upon by science and industry, and the like.


"You can lead a horse to water, but you can't make him think..."

Bob Smerbeck
Bob Smerbeck

@Bart Hoekstra @Harold Seneker   There is increasing research (Trenberth, Meehl, Kosaka, Shang-Ping Xie)  that the Pacific Decadal Oscillation is playing a bigger role in the global surface temperature "hiatus".  Why was this not incorporated into the climate models, it has a pronounced cycle going back to the 1920s. A PDO phase can last 30 years which could extend the "hiatus" until 2030. Persistence would  have another warm cycle mid century will follow followed by a cool cycle before the end of the century which would cause perhaps a degree of warming by 2100. 

Dwayne LaGrou
Dwayne LaGrou

I read the article you mentioned and it sounds like they are on the right track to produce a "Carbon Neutral" fuel that is a direct replacement for gasoline or diesel fuel. By using wind or solar power they could turn things around for humanity in a hurry. Thanks for the heads up on that article. Sounds VERY Promising.

Dwayne LaGrou
Dwayne LaGrou

As far as the collection goes, power companies are already collecting the CO2 from their exhaust, they are just finding it difficult to find a place to put it. When they are already trying to inject it underground for long term storage it just makes sense to try injecting in one of the hundreds of mine fires to see if it helps. Weather it succeds or not, it is better than just ignoring the fires and letting them burn until they run out of fuel!

Peter S.
Peter S.

@Jim Satterfield @Peter S.  It's understandable that folks cannot see the connection between meteorology and climatology. 

By your hypothesis "Meteorology != climatology", one can conclude that weather events are not related to climate change!

Peter S.
Peter S.

@John Patt @Peter S. I would state that I am not denying the existence of climate change. Constant change is one of the primary reasons that field is so fascinating to study, and is something professionals in the field understand at the onset of their engagement. 

My comments are about poor scientific basis for drawing conclusions with little understanding of the fundamentals principles at work. 

Craig Miller ッ
Craig Miller ッ

Right, the models are not valid for formulating policies. However, putting policies in place to reduce emissions and become more sustainable is like the world being your friends house during a party and when everyone leaves, they try their best to leave the house as they had found it.

Cameron Spitzer
Cameron Spitzer

@Harold Seneker@Cameron Spitzer That's why we don't let the policy makers operate the models themselves.  Instead, we let the people who know the most about them operate them and interpret their results, and then their competitors (anonymously) try to tear it all apart.   Then, if the competitors fail, the science gets published.

And when that happens a lot for a long time you get something solid enough that you'd be insane NOT to inform public policy with it.  As seems to be the case with climate science.  The models have been fairly usable for a decade or two, and the uncertainties are well understood.  But the public policy response is trivial compared to what's needed.

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