The first portion of this article is commentary by the editor of "EcoWorld", and the second is an essay about the dangers of the current state of alarmism about global warming. Both are very well worth reading.
Peter
Source:
The Fluid Envelope
A CASE AGAINST CLIMATE ALARMISM
by Richard Lindzen
Editor's Note: Our charter to report on clean technology and the status of species and ecosystems seems to always bring us back to one overriding distraction - global warming alarm - and small wonder. We are in the midst of one of the most dramatic transformations of political economy in the history of the world - and nobody is watching. "The debate is over on global warming," goes the consensus, and even if that were a healthy or accurate notion, why has this consensus translated into hardly any vigorous debate over what would be a rational response?
Despite ongoing rhetoric to the contrary from virtually every environmental nonprofit in existance, the United States has been an extraordinarily responsible nation. We listened to our environmental movement; we institutionalized it. On every front there has been huge progress over the past 30-40 years. Our air and water are orders of magnitude cleaner even though our population has doubled. Our landfills our ultra-safe. We have set aside vast tracts of wilderness, rescued countless endangered species. Our food supply is scrupulously monitored. And every year our technology and our prosperity delivers new options to eliminate more pollution and live healthier lives. So what happened?
In the rest of the world there is also reason for great optimism, despite some discouraging challenges that continue to grip humanity. Human population is voluntarily leveling off, so that within 25-30 years the number of people on planet earth will peak at around 8.5 billion - and every time the projection is revisited, that estimate drops. At an even faster pace, humanity is urbanizing - and this voluntary movement is taking people out of the vast and potentially endangered forests and other biomes faster than population increase replaces them. Land is becoming abundant again. So what's wrong?
Technology promises abundant energy within a few decades, using clean fossil fuel as we systematically replace it with solar, nuclear, run-of-river hydroelectric, enhanced geothermal, wind, possibly biofuel. Technology promises abundant water within a few decades, as we learn how to recycle every drop of water used in the urban environment, convert many crops to drip irrigation, and develop massive desalination capacity. So why don't we get to work?
The reason is because of global warming alarm. The bells of warning are ringing so loud that CO2 is all that matters anymore. Want to stop using petroleum? Then burn the rainforests for biofuel. Want to stop using coal? Then forget about installing affordable scrubbers to remove the soot that billows from coal fired power plants across burgeoning Asia - why clean up something that needs to be shut down? Want to save allegedly scarce open space? Then cram everyone into ultra-high density "infill" and destroy every semi rural neighborhood in the western world. Make housing unaffordable, then mandate taxpayer-subsidized affordable housing. And do it all in the name of reducing CO2 emissions.
Today, after reading two documents from the website of the Attorney General of California, "Mitigation Measures," and "Global Warming Contrarians and the Falsehoods they Promote," I became so alarmed at what we are willingly, blindly bringing upon ourselves because of all this CO2 alarm that I contacted Dr. Richard Lindzen, who has already contributed two lengthy articles to EcoWorld, "Current Behavior of Global Mean Surface Temperature," and "Is There a Basis for Global Warming Alarm?"
I asked Dr. Lindzen if he still held the views he does. He replied emphatically in the affirmative, and sent me the article that follows. Dr. Lindzen, along with Dr. Roger Pielke, Sr., with whom EcoWorld recently published the exclusive "Interview with Dr. Roger Pielke, Sr.," are both internationally respected atmospheric scientists. And both of them, in somewhat different ways, are quite concerned about the overemphasis on CO2.
Anyone who is championing extreme measures to reduce anthropogenic CO2 should attempt for themselves to understand the science. As Dr. Lindzen wrote me earlier today, policymakers such as Jerry Brown and Arnold Schwarzenegger "can be excused given the degree to which the environmental movement has taken over the professional societies."
"Science" has become the trump card that drowns out reason - what great irony. And the scientific establishment itself has become politicized. And if you read the mitigation measures being proposed, just imagine if there was nothing we could do to affect global warming - which even some of the lead authors of the IPCC studies themselves acknowlege - and see if you want to live in the brave new world we are leading ourselves into by our own gullible noses.
Dramatic and positive global economic and technological developments, along with voluntary and irreversible global demographic trends, are about to deliver us a future where we enjoy unprecedented environmental health, abundance and prosperity. But to do this we need to preserve our economic and personal freedoms. Will the measures being proposed - especially in trendsetting California - fruitlessly combat a problem that doesn't exist, crush economic growth and trample on individual freedom, and rob humanity of this hopeful destiny? - Ed "Redwood" Ring
The Fluid Envelope - A Case Against Climate Alarmism by Dr. Richard Lindzen, February 2008
California Governor Arnold Schwarzenegger
What will be his legacy?
The notion of a static, unchanging climate is foreign to the history of the earth or any other planet with a fluid envelope. The fact that the developed world went into hysterics over changes in global mean temperature of a few tenths of a degree will astound future generations.
Such hysteria simply represents the scientific illiteracy of much of the public, the susceptibility of the public to the Goebbelian substitution of repetition for truth, and the exploitation of these weaknesses by politicians, environmental promoters, and, after 20 years of media drum beating, many others as well.
Climate is always changing. We have had ice ages and warmer periods when alligators were found in Spitzbergen. Ice ages have occurred in a hundred thousand year cycle for the last 700 thousand years, and previous warm periods appear to have been warmer than the present despite CO2 levels being lower than they are now. More recently, we have had the medieval warm period and the little ice age. During the latter, alpine glaciers advanced to the chagrin of overrun villages.
Since the beginning of the 19th Century these glaciers have been retreating. Frankly, we dont fully understand either the advance or the retreat. For small changes in climate associated with tenths of a degree, there is no need for any external cause. The earth is never exactly in equilibrium. The motions of the massive oceans where heat is moved between deep layers and the surface provides variability on time scales from years to centuries. Recent work (Tsonis et al, 2007), suggests that this variability is enough to account for all climate change since the 19th Century. Supporting the notion that man has not been the cause of this unexceptional change in temperature is the fact that there is a distinct signature to greenhouse warming: surface warming should be accompanied by warming in the tropics around an altitude of about 9km that is about 2.5 times greater than at the surface.
Measurements show that warming at these levels is only about 3/4 of what is seen at the surface, implying that only about a third of the surface warming is associated with the greenhouse effect, and, quite possibly, not all of even this really small warming is due to man. This further implies that all models predicting significant warming are greatly overestimating warming. This should not be surprising. According to the UNs Intergovernmental Panel on Climate Change, the greenhouse forcing from man made greenhouse gases is already about 86 % of what one expects from a doubling of CO2 (with about half coming from methane, nitrous oxide, freons and ozone), and alarming predictions depend on models for which the sensitivity to a doubling for CO2 is greater than 2C which implies that we should already have seen much more warming than we have seen thus far, even if all the warming we have seen so far were due to man.
This contradiction is rendered more acute by the fact that there has been no significant global warming for the last ten years. Modelers defend this situation by arguing that aerosols have cancelled much of the warming, and that models adequately account for natural unforced internal variability. However, a recent paper (Ramanathan, 2007) points out that aerosols can warm as well as cool, while scientists at the UKs Hadley Centre for Climate Research recently noted that their model did not appropriately deal with natural internal variability thus demolishing the basis for the IPCCs iconic attribution. Interestingly (though not unexpectedly), the British paper did not stress this. Rather, they speculated that natural internal variability might step aside in 2009, allowing warming to resume. Resume? Thus, the fact that warming has ceased for the past decade is acknowledged.
Whether or not someone is a climate alarmistﾠshould have nobearing on the strength or purity of their environmentalist convictions. (Read "Global Warming Questions")
Given that the evidence (and I have noted only a few of many pieces of evidence) strongly suggests that anthropogenic warming has been greatly exaggerated, the basis for alarm due to such warming is similarly diminished.
However, the really important point is that the case for alarm would still be weak even if anthropogenic global warming were significant. Polar bears, arctic summer sea ice, regional droughts and floods, coral bleaching, hurricanes, alpine glaciers, malaria, etc. etc. all depend not on some global average of surface temperature, but on a huge number of regional variables including temperature, humidity, cloud cover, precipitation, and direction and magnitude of wind.
The state of the ocean is also often crucial. Our ability to forecast any of these over periods beyond a few days is minimal. Yet, each catastrophic forecast depends on each of these being in a specific range. The odds of any specific catastrophe actually occurring is almost zero. This was equally true for earlier forecasts: famine for the 1980's, global cooling in the 1970's, Y2K and many others. Regionally, year to year fluctuations in temperature are over four times larger than fluctuations in the global mean. Much of this variation has to be independent of the global mean; otherwise the global mean would vary much more.
This is simply to note that factors other than global warming are more important to any specific situation. This is not to say that disasters will not occur; they always have occurred and this will not change in the future. Fighting global warming with symbolic gestures will certainly not change this. However, history tells us that greater wealth and development can profoundly increase our resilience.
Given the above, one may reasonably ask why there is the current alarm, and, in particular, why the astounding upsurge in alarmism of the past 2 years. When an issue like global warming is around for over twenty years, numerous agendas are developed to exploit the issue.
California Attorney General Jerry Brown
What is his dream?
The interests of the environmental movement in acquiring more power and influence are reasonably clear. So too are the interests of bureaucrats for whom control of CO2 is a dream-come-true.
After all, CO2 is a product of breathing itself. Politicians can see the possibility of taxation that will be cheerfully accepted because it is necessary for saving the world. Nations have seen how to exploit this issue in order to gain competitive advantages. But, by now, things have gone much further.
The case of ENRON is illustrative in this respect. Before disintegrating in a pyrotechnic display of unscrupulous manipulation, ENRON had been one of the most intense lobbyists for Kyoto. It had hoped to become a trading firm dealing in carbon emission rights. This was no small hope. These rights are likely to amount to over a trillion dollars, and the commissions will run into many billions. Hedge funds are actively examining the possibilities. It is probably no accident that Gore, himself, is associated with such activities . The sale of indulgences is already in full swing with organizations selling offsets to one's carbon footprint while sometimes acknowledging that the offsets are irrelevant.
The possibilities for corruption are immense. Archer Daniels Midland (America's largest agribusiness) has successfully lobbied for ethanol requirements for gasoline, and the resulting demand for ethanol is already leading to large increases in corn prices and associated hardship in the developing world (not to mention poorer car performance).
And finally, there are the numerous well meaning individuals who have allowed propagandists to convince them that in accepting the alarmist view of anthropogenic climate change, they are displaying intelligence and virtue For them, their psychic welfare is at stake.
With all this at stake, one can readily suspect that there might be a sense of urgency provoked by the possibility that warming may have ceased. For those committed to the more venal agendas, the need to act soon, before the public appreciates the situation, is real indeed.
About the Author: Richard S. Lindzen is the Alfred P. Sloan Professor of Atmospheric Science at the Massachusetts Institute of Technology(http://web.mit.edu). This article is reprinted here with permission from the author.
Showing posts with label Richard S. Lindzen. Show all posts
Showing posts with label Richard S. Lindzen. Show all posts
Monday, February 11, 2008
Friday, November 16, 2007
University Students Begin To Hear The Truth.......
Now it seems students at our major colleges (In this case Colgate University) are beginning to hear that there is some debate about the causes of global warming. The mainstream media is getting the message, students are starting to ask questions, and the man-caused global warming true believers and being called out. Things are looking up.
Peter
Lindzen says Chill out: Global Warming skeptic speaks at Colgate University,
NYStudents and faculty crowded into the Henshaw Lecture Room in Lathrop Hall on Thursday afternoon to hear a controversial lecture by Massachusetts Institute of Technology Alfred P. Sloan Professor of Meteorology Richard Lindzen. Colgate Professor of Political Science, Presidential Scholar and Director of the Center for Freedom and Western Civilization Robert Kraynak, who introduced Lindzen, explained that the original title of the lecture had been "Global Warming: Science and Moral Responsibility" but that he and Lindzen had come up with a better one: "Global Warming: Who's to Blame, Human Activities or Natural Causes?"
Lindzen is one of the most noted and prolific detractors from what Kraynak described as the "popular wisdom of global warming." Lindzen began by saying that he had "always assumed that talking about the weather was a source of boredom." He then began to explain his real concern that too much alarmism surrounds the topic of global climate change. His first goal: to debunk Al Gore.
He recalled that all schools in the United Kingdom had recently been required to show Gore's film An Inconvenient Truth. He noted that a judge ruled that all presentations of the movie be accompanied by a presentation of critiques and explanations of some of the movie's scientific exaggerations. Lindzen cited one of Gore's statements in that film that a melting of the icecaps at either Greenland or West Antarctica would result in a sea level rise of 20 feet "in the near future." The judge, according to Lindzen, said, "this remark was distinctly alarmist" and that Gore's predicted result would take millennia to come about.
Lindzen called Gore's statement that "warming is real and caused by humans," a "masterful example of creative ambiguity." "The points of agreement [on warming] have no discernable connection to the alarm," Lindzen said. "If it turns out that we don't have warming or that it is not due to man, that has implications that the association of alarm with greenhouse gas emissions is baseless."
His next point questioned both the derivation and meaning of the popular model of the "hockey stick" graph of weather change, which shows a dramatic increase in temperature rise in recent history. "Even if you call that [rise] unprecedented, it is still too small to suggest alarm," Lindzen said. After bringing up the scientific inaccuracies in inferences Gore drew from a different graph in his book, Lindzen moved to a different argument against the catastrophic consequences that some predict will come as a result of global warming. "Any prediction of catastrophe is extremely unlikely," Lindzen said.
He cited the panic in the 1970s over the prediction of catastrophic American famine in the 1980s, which turned out to be false, as well as the infamous prediction of the Y2K disaster. "These predictions of catastrophe come up episodically and they are always wrong because they have wrong linkages," Lindzen said.
He then projected a model of the linkages leading from cause -- carbon dioxide emissions -- to effect -- disastrous warming effects -- in global warming and noted that the likelihood of each affecting the next was tiny, and that, in the end, the probability of any major effect of global warming was "astronomically small."
Lindzen also brought up how the media has manipulated scientific fact and consensus to promote global warming. He then went into a very scientific debunking of the sensitivity of climate to greenhouse gases, concluding that, "from a religious point-of-view, the Earth is well-designed." He compared the attribution of global warming to greenhouse gases to the intelligent design theory. "We can't think of anything else, so there must be an intelligent designer," he said."
"There is nothing happening in nature that suggests anything urgent," Lindzen said. He then described all of the agendas of people who would be harmed "if you suddenly heard that there was no such thing as harmful global warming," including the Nobel Prize Committee, which recently gave the Nobel Peace Prize to Al Gore, the environmental movement and science, alternative energy, the United Nations, trial lawyers "looking to make carbon the next tobacco" and individuals who have adopted this issue as a personal cause. "The alarmist dogmas of the past 20 years are almost certainly false or misleading," Lindzen said in conclusion.
A panel of three Colgate professors, Professor of Geography Adam Burnett, Assistant Professor of Chemistry Ephraim Woods and Professor of Economics and Environmental Studies Bob Turner were then allowed to ask Lindzen questions, followed by a question-and-answer session for students. "I think it's good to have folks on campus that have a strong point of view," Woods said. "But [Lindzen] doesn't engage in a discussion very well. He is very quick to reject some pieces of data as bad science or somehow contrived when they don't meet with his point of view."
"I thought that he made a very compelling argument," first-year Mike Abrahamson, who attended the lecture on suggestion from a professor, said. "I would say as someone who knows very little about the science on either side that it was very convincing." "It's nice that we now have viewpoints from both extreme sides of the issue," first-year Alyssa Perez said, referring to the lecture and to The Weather Makers, the required reading for incoming first-years. "Now I'd like to hear from someone more in the middle of the issue."
"I think this lecture helped a lot," Director of Summer Programs and Lecturer in University Studies Matt Leone, who suggested the lecture to his students, including Abrahamson and Perez, said. "Lindzen is an extraordinarily adept meteorologist. He is clearly very knowledgeable and passionate about his subject...This is the kind of thing that matters a lot. I can't be convinced one way or another because I'm not a scientist, but I do feel as a citizen that I should do my best to understand the subject as best I can."
Source
Peter
Lindzen says Chill out: Global Warming skeptic speaks at Colgate University,
NYStudents and faculty crowded into the Henshaw Lecture Room in Lathrop Hall on Thursday afternoon to hear a controversial lecture by Massachusetts Institute of Technology Alfred P. Sloan Professor of Meteorology Richard Lindzen. Colgate Professor of Political Science, Presidential Scholar and Director of the Center for Freedom and Western Civilization Robert Kraynak, who introduced Lindzen, explained that the original title of the lecture had been "Global Warming: Science and Moral Responsibility" but that he and Lindzen had come up with a better one: "Global Warming: Who's to Blame, Human Activities or Natural Causes?"
Lindzen is one of the most noted and prolific detractors from what Kraynak described as the "popular wisdom of global warming." Lindzen began by saying that he had "always assumed that talking about the weather was a source of boredom." He then began to explain his real concern that too much alarmism surrounds the topic of global climate change. His first goal: to debunk Al Gore.
He recalled that all schools in the United Kingdom had recently been required to show Gore's film An Inconvenient Truth. He noted that a judge ruled that all presentations of the movie be accompanied by a presentation of critiques and explanations of some of the movie's scientific exaggerations. Lindzen cited one of Gore's statements in that film that a melting of the icecaps at either Greenland or West Antarctica would result in a sea level rise of 20 feet "in the near future." The judge, according to Lindzen, said, "this remark was distinctly alarmist" and that Gore's predicted result would take millennia to come about.
Lindzen called Gore's statement that "warming is real and caused by humans," a "masterful example of creative ambiguity." "The points of agreement [on warming] have no discernable connection to the alarm," Lindzen said. "If it turns out that we don't have warming or that it is not due to man, that has implications that the association of alarm with greenhouse gas emissions is baseless."
His next point questioned both the derivation and meaning of the popular model of the "hockey stick" graph of weather change, which shows a dramatic increase in temperature rise in recent history. "Even if you call that [rise] unprecedented, it is still too small to suggest alarm," Lindzen said. After bringing up the scientific inaccuracies in inferences Gore drew from a different graph in his book, Lindzen moved to a different argument against the catastrophic consequences that some predict will come as a result of global warming. "Any prediction of catastrophe is extremely unlikely," Lindzen said.
He cited the panic in the 1970s over the prediction of catastrophic American famine in the 1980s, which turned out to be false, as well as the infamous prediction of the Y2K disaster. "These predictions of catastrophe come up episodically and they are always wrong because they have wrong linkages," Lindzen said.
He then projected a model of the linkages leading from cause -- carbon dioxide emissions -- to effect -- disastrous warming effects -- in global warming and noted that the likelihood of each affecting the next was tiny, and that, in the end, the probability of any major effect of global warming was "astronomically small."
Lindzen also brought up how the media has manipulated scientific fact and consensus to promote global warming. He then went into a very scientific debunking of the sensitivity of climate to greenhouse gases, concluding that, "from a religious point-of-view, the Earth is well-designed." He compared the attribution of global warming to greenhouse gases to the intelligent design theory. "We can't think of anything else, so there must be an intelligent designer," he said."
"There is nothing happening in nature that suggests anything urgent," Lindzen said. He then described all of the agendas of people who would be harmed "if you suddenly heard that there was no such thing as harmful global warming," including the Nobel Prize Committee, which recently gave the Nobel Peace Prize to Al Gore, the environmental movement and science, alternative energy, the United Nations, trial lawyers "looking to make carbon the next tobacco" and individuals who have adopted this issue as a personal cause. "The alarmist dogmas of the past 20 years are almost certainly false or misleading," Lindzen said in conclusion.
A panel of three Colgate professors, Professor of Geography Adam Burnett, Assistant Professor of Chemistry Ephraim Woods and Professor of Economics and Environmental Studies Bob Turner were then allowed to ask Lindzen questions, followed by a question-and-answer session for students. "I think it's good to have folks on campus that have a strong point of view," Woods said. "But [Lindzen] doesn't engage in a discussion very well. He is very quick to reject some pieces of data as bad science or somehow contrived when they don't meet with his point of view."
"I thought that he made a very compelling argument," first-year Mike Abrahamson, who attended the lecture on suggestion from a professor, said. "I would say as someone who knows very little about the science on either side that it was very convincing." "It's nice that we now have viewpoints from both extreme sides of the issue," first-year Alyssa Perez said, referring to the lecture and to The Weather Makers, the required reading for incoming first-years. "Now I'd like to hear from someone more in the middle of the issue."
"I think this lecture helped a lot," Director of Summer Programs and Lecturer in University Studies Matt Leone, who suggested the lecture to his students, including Abrahamson and Perez, said. "Lindzen is an extraordinarily adept meteorologist. He is clearly very knowledgeable and passionate about his subject...This is the kind of thing that matters a lot. I can't be convinced one way or another because I'm not a scientist, but I do feel as a citizen that I should do my best to understand the subject as best I can."
Source
Saturday, July 14, 2007
Can Increasing Carbon Dioxide Cause Climate Change?
The following paper by Richard S. Lindzen, Professor and Climate Scientist at MIT quite clearly states that he sees no connection between increasing atmospheric carbon dioxide levels and global warming. The article, although now ten years old, still reflects his current position on the subject.
Prof. Lindzen is denounced as a global warming "skeptic", but it is difficult to argue with his credentials and his experience.
Peter
Proc. Natl. Acad. Sci. USA
Vol. 94, pp. 8335–8342, August 1997
Colloquium Paper
This paper was presented at a colloquium entitled “Carbon Dioxide and Climate Change,” organized by Charles D.
Keeling, held November 13–15, 1995, at the National Academy of Sciences, Irvine, CA.
Can increasing carbon dioxide cause climate change?
RICHARD S. LINDZEN
Building 54, Room 1720, Massachusetts Institute of Technology, Cambridge, MA 02139
ABSTRACT
The title suggested for this paper (by Dave Keeling) is tantalizing for its ambiguity. At some level, the answer is philosophically trivial. After all, our knowledge is rarely so perfect
that we can say anything is absolutely impossible. In connection with this question we can go a bit further, and state that increasing CO2 is likely to cause some climate change, and that
the resulting change will involve average warming of the earth. However, this answer is almost as trivial as the first.
Conclusion
The brief conclusion of this paper is that current GCMs are inadequate for the purpose of convincingly determining whether the small changes in TOA flux associated with an
increase in CO2 are capable of producing significant climate change. However, we may not be dependent on uncertain models to ascertain climate sensitivity. Observations can potentially
directly and indirectly be used to evaluate climate sensitivity to forcing of the sort produced by increasing CO2 even without improved GCMs.
Prof. Lindzen is denounced as a global warming "skeptic", but it is difficult to argue with his credentials and his experience.
Peter
Proc. Natl. Acad. Sci. USA
Vol. 94, pp. 8335–8342, August 1997
Colloquium Paper
This paper was presented at a colloquium entitled “Carbon Dioxide and Climate Change,” organized by Charles D.
Keeling, held November 13–15, 1995, at the National Academy of Sciences, Irvine, CA.
Can increasing carbon dioxide cause climate change?
RICHARD S. LINDZEN
Building 54, Room 1720, Massachusetts Institute of Technology, Cambridge, MA 02139
ABSTRACT
The realistic physical functioning of the greenhouse effect is reviewed, and the role of dynamic transport and water vapor is identified. Model errors and uncertainties are quantitatively compared with the forcing due to doubling CO2, and they are shown to be too large for reliable
model evaluations of climate sensitivities. The possibility of directly measuring climate sensitivity is reviewed.
model evaluations of climate sensitivities. The possibility of directly measuring climate sensitivity is reviewed.
A direct approach using satellite data to relate changes in globally averaged radiative flux changes at the top of the atmosphere to naturally occurring changes in global mean temperature is described. Indirect approaches to evaluating climate sensitivity involving the response to volcanic eruptions and Eocene climate change are also described. Finally, it is explained how,
in principle, a climate that is insensitive to gross radiative forcing as produced by doubling CO2 might still be able to undergo major changes of the sort associated with ice ages and
equable climates.
in principle, a climate that is insensitive to gross radiative forcing as produced by doubling CO2 might still be able to undergo major changes of the sort associated with ice ages and
equable climates.
The title suggested for this paper (by Dave Keeling) is tantalizing for its ambiguity. At some level, the answer is philosophically trivial. After all, our knowledge is rarely so perfect
that we can say anything is absolutely impossible. In connection with this question we can go a bit further, and state that increasing CO2 is likely to cause some climate change, and that
the resulting change will involve average warming of the earth. However, this answer is almost as trivial as the first.
The climate is always undergoing change, and if the changes due to increasing CO2 are smaller than the natural variability, then these changes will be of only modest concern except as an
exercise in weak signal detection. The more serious question then is do we expect increasing CO2 to produce sufficiently large changes in climate so as to be clearly discernible and of
consequence for the affairs of humans and the ecosystem of which we are part. This is the question I propose to approach in this paper.
exercise in weak signal detection. The more serious question then is do we expect increasing CO2 to produce sufficiently large changes in climate so as to be clearly discernible and of
consequence for the affairs of humans and the ecosystem of which we are part. This is the question I propose to approach in this paper.
I will first consider the question of whether current model predictions are likely to be credible. We will see why this is unlikely at best. I will then show how we might estimate and bound climate sensitivity both directly and indirectly from existing data. Finally, I will consider the relationship of changes in mean temperature to changes in the structure of climate. It has been suggested that small changes in mean temperature are important because major changes in
past climate were associated with major changes in the equator-to-pole temperature difference, but only small changes in the mean temperature. I will argue that the changes in mean
temperature may be only residuals of the changes in the meridional temperature distribution rather than the cause.
past climate were associated with major changes in the equator-to-pole temperature difference, but only small changes in the mean temperature. I will argue that the changes in mean
temperature may be only residuals of the changes in the meridional temperature distribution rather than the cause.
(continued)...........................
Conclusion
The brief conclusion of this paper is that current GCMs are inadequate for the purpose of convincingly determining whether the small changes in TOA flux associated with an
increase in CO2 are capable of producing significant climate change. However, we may not be dependent on uncertain models to ascertain climate sensitivity. Observations can potentially
directly and indirectly be used to evaluate climate sensitivity to forcing of the sort produced by increasing CO2 even without improved GCMs.
The observations needed for direct assessment are, indeed, observations that we are currently capable of making, and it is possible that the necessary observations may already be in hand, though the accuracy requirements may be greater than current data provide. Still,the importance of the question suggests that such avenues be adequately explored. Since the feedbacks involved in climate sensitivity are atmospheric, they are associated with short time scales. Oceanic delays are irrelevant, since observed surface temperatures are forcing the flux changes we are concerned with. The needed length of record must be determined empirically.
Indirect estimates, based on response to volcanos, suggest sensitivity may be as small as 0.3–0.5°C for a doubling of CO2, which is well within the range of natural variability. This is not to suggest that such change cannot be detected; rather, it is a statement that the anticipated change is well within the range of what the earth regularly deals with. It is further noted that the common assertion that even small changes in mean temperature can lead to major changes in climate distribution is ill-founded and, likely, wrong.
Wednesday, July 11, 2007
It amazes me how Prof. Lindzen is ignored and effectively silenced by those who believe man is causing global warming. This article was in the Wall Street Journal, so some people are listening.
Peter
EARTH IN THE BALANCE
Don't Believe the Hype Al Gore is wrong. There's no "consensus" on global warming.
BY RICHARD S. LINDZEN
Sunday, July 2, 2006 12:01 a.m. EDT
According to Al Gore's new film "An Inconvenient Truth," we're in for "a planetary emergency": melting ice sheets, huge increases in sea levels, more and stronger hurricanes, and invasions of tropical disease, among other cataclysms--unless we change the way we live now.
Bill Clinton has become the latest evangelist for Mr. Gore's gospel, proclaiming that current weather events show that he and Mr. Gore were right about global warming, and we are all suffering the consequences of President Bush's obtuseness on the matter. And why not? Mr. Gore assures us that "the debate in the scientific community is over."
That statement, which Mr. Gore made in an interview with George Stephanopoulos on ABC, ought to have been followed by an asterisk. What exactly is this debate that Mr. Gore is referring to? Is there really a scientific community that is debating all these issues and then somehow agreeing in unison? Far from such a thing being over, it has never been clear to me what this "debate" actually is in the first place.
The media rarely help, of course. When Newsweek featured global warming in a 1988 issue, it was claimed that all scientists agreed. Periodically thereafter it was revealed that although there had been lingering doubts beforehand, now all scientists did indeed agree. Even Mr. Gore qualified his statement on ABC only a few minutes after he made it, clarifying things in an important way. When Mr. Stephanopoulos confronted Mr. Gore with the fact that the best estimates of rising sea levels are far less dire than he suggests in his movie, Mr. Gore defended his claims by noting that scientists "don't have any models that give them a high level of confidence" one way or the other and went on to claim--in his defense--that scientists "don't know. . . . They just don't know."
So, presumably, those scientists do not belong to the "consensus." Yet their research is forced, whether the evidence supports it or not, into Mr. Gore's preferred global-warming template--namely, shrill alarmism. To believe it requires that one ignore the truly inconvenient facts. To take the issue of rising sea levels, these include: that the Arctic was as warm or warmer in 1940; that icebergs have been known since time immemorial; that the evidence so far suggests that the Greenland ice sheet is actually growing on average. A likely result of all this is increased pressure pushing ice off the coastal perimeter of that country, which is depicted so ominously in Mr. Gore's movie.
In the absence of factual context, these images are perhaps dire or alarming.
They are less so otherwise. Alpine glaciers have been retreating since the early 19th century, and were advancing for several centuries before that. Since about 1970, many of the glaciers have stopped retreating and some are now advancing again. And, frankly, we don't know why.
The other elements of the global-warming scare scenario are predicated on similar oversights. Malaria, claimed as a byproduct of warming, was once common in Michigan and Siberia and remains common in Siberia--mosquitoes don't require tropical warmth. Hurricanes, too, vary on multidecadal time scales; sea-surface temperature is likely to be an important factor. This temperature, itself, varies on multidecadal time scales. However, questions concerning the origin of the relevant sea-surface temperatures and the nature of trends in hurricane intensity are being hotly argued within the profession.
Even among those arguing, there is general agreement that we can't attribute any particular hurricane to global warming. To be sure, there is one exception, Greg Holland of the National Center for Atmospheric Research in Boulder, Colo., who argues that it must be global warming because he can't think of anything else. While arguments like these, based on lassitude, are becoming rather common in climate assessments, such claims, given the primitive state of weather and climate science, are hardly compelling.
A general characteristic of Mr. Gore's approach is to assiduously ignore the fact that the earth and its climate are dynamic; they are always changing even without any external forcing. To treat all change as something to fear is bad enough; to do so in order to exploit that fear is much worse. Regardless, these items are clearly not issues over which debate is ended--at least not in terms of the actual science.
A clearer claim as to what debate has ended is provided by the environmental journalist Gregg Easterbrook. He concludes that the scientific community now agrees that significant warming is occurring, and that there is clear evidence of human influences on the climate system. This is still a most peculiar claim. At some level, it has never been widely contested. Most of the climate community has agreed since 1988 that global mean temperatures have increased on the order of one degree Fahrenheit over the past century, having risen significantly from about 1919 to 1940, decreased between 1940 and the early '70s, increased again until the '90s, and remaining essentially flat since 1998.
There is also little disagreement that levels of carbon dioxide in the atmosphere have risen from about 280 parts per million by volume in the 19th century to about 387 ppmv today. Finally, there has been no question whatever that carbon dioxide is an infrared absorber (i.e., a greenhouse gas--albeit a minor one), and its increase should theoretically contribute to warming. Indeed, if all else were kept equal, the increase in carbon dioxide should have led to somewhat more warming than has been observed, assuming that the small observed increase was in fact due to increasing carbon dioxide rather than a natural fluctuation in the climate system. Although no cause for alarm rests on this issue, there has been an intense effort to claim that the theoretically expected contribution from additional carbon dioxide has actually been detected.
Given that we do not understand the natural internal variability of climate change, this task is currently impossible. Nevertheless there has been a persistent effort to suggest otherwise, and with surprising impact. Thus, although the conflicted state of the affair was accurately presented in the 1996 text of the Intergovernmental Panel on Climate Change, the infamous "summary for policy makers" reported ambiguously that "The balance of evidence suggests a discernible human influence on global climate." This sufficed as the smoking gun for Kyoto.
The next IPCC report again described the problems surrounding what has become known as the attribution issue: that is, to explain what mechanisms are responsible for observed changes in climate. Some deployed the lassitude argument--e.g., we can't think of an alternative--to support human attribution. But the "summary for policy makers" claimed in a manner largely unrelated to the actual text of the report that "In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations."
In a similar vein, the National Academy of Sciences issued a brief (15-page) report responding to questions from the White House. It again enumerated the difficulties with attribution, but again the report was preceded by a front end that ambiguously claimed that "The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability." This was sufficient for CNN's Michelle Mitchell to presciently declare that the report represented a "unanimous decision that global warming is real, is getting worse and is due to man. There is no wiggle room." Well, no.
More recently, a study in the journal Science by the social scientist Nancy Oreskes claimed that a search of the ISI Web of Knowledge Database for the years 1993 to 2003 under the key words "global climate change" produced 928 articles, all of whose abstracts supported what she referred to as the consensus view. A British social scientist, Benny Peiser, checked her procedure and found that only 913 of the 928 articles had abstracts at all, and that only 13 of the remaining 913 explicitly endorsed the so-called consensus view. Several actually opposed it.
Even more recently, the Climate Change Science Program, the Bush administration's coordinating agency for global-warming research, declared it had found "clear evidence of human influences on the climate system." This, for Mr. Easterbrook, meant: "Case closed."
What exactly was this evidence? The models imply that greenhouse warming should impact atmospheric temperatures more than surface temperatures, and yet satellite data showed no warming in the atmosphere since 1979. The report showed that selective corrections to the atmospheric data could lead to some warming, thus reducing the conflict between observations and models descriptions of what greenhouse warming should look like. That, to me, means the case is still very much open.
So what, then, is one to make of this alleged debate? I would suggest at least three points.
First, nonscientists generally do not want to bother with understanding the science. Claims of consensus relieve policy types, environmental advocates and politicians of any need to do so. Such claims also serve to intimidate the public and even scientists--especially those outside the area of climate dynamics. Secondly, given that the question of human attribution largely cannot be resolved, its use in promoting visions of disaster constitutes nothing so much as a bait-and-switch scam. That is an inauspicious beginning to what Mr. Gore claims is not a political issue but a "moral" crusade.
Lastly, there is a clear attempt to establish truth not by scientific methods but by perpetual repetition. An earlier attempt at this was accompanied by tragedy. Perhaps Marx was right. This time around we may have farce--if we're lucky.
Mr. Lindzen is the Alfred P. Sloan Professor of Atmospheric Science at MIT.
Peter
EARTH IN THE BALANCE
Don't Believe the Hype Al Gore is wrong. There's no "consensus" on global warming.
BY RICHARD S. LINDZEN
Sunday, July 2, 2006 12:01 a.m. EDT
According to Al Gore's new film "An Inconvenient Truth," we're in for "a planetary emergency": melting ice sheets, huge increases in sea levels, more and stronger hurricanes, and invasions of tropical disease, among other cataclysms--unless we change the way we live now.
Bill Clinton has become the latest evangelist for Mr. Gore's gospel, proclaiming that current weather events show that he and Mr. Gore were right about global warming, and we are all suffering the consequences of President Bush's obtuseness on the matter. And why not? Mr. Gore assures us that "the debate in the scientific community is over."
That statement, which Mr. Gore made in an interview with George Stephanopoulos on ABC, ought to have been followed by an asterisk. What exactly is this debate that Mr. Gore is referring to? Is there really a scientific community that is debating all these issues and then somehow agreeing in unison? Far from such a thing being over, it has never been clear to me what this "debate" actually is in the first place.
The media rarely help, of course. When Newsweek featured global warming in a 1988 issue, it was claimed that all scientists agreed. Periodically thereafter it was revealed that although there had been lingering doubts beforehand, now all scientists did indeed agree. Even Mr. Gore qualified his statement on ABC only a few minutes after he made it, clarifying things in an important way. When Mr. Stephanopoulos confronted Mr. Gore with the fact that the best estimates of rising sea levels are far less dire than he suggests in his movie, Mr. Gore defended his claims by noting that scientists "don't have any models that give them a high level of confidence" one way or the other and went on to claim--in his defense--that scientists "don't know. . . . They just don't know."
So, presumably, those scientists do not belong to the "consensus." Yet their research is forced, whether the evidence supports it or not, into Mr. Gore's preferred global-warming template--namely, shrill alarmism. To believe it requires that one ignore the truly inconvenient facts. To take the issue of rising sea levels, these include: that the Arctic was as warm or warmer in 1940; that icebergs have been known since time immemorial; that the evidence so far suggests that the Greenland ice sheet is actually growing on average. A likely result of all this is increased pressure pushing ice off the coastal perimeter of that country, which is depicted so ominously in Mr. Gore's movie.
In the absence of factual context, these images are perhaps dire or alarming.
They are less so otherwise. Alpine glaciers have been retreating since the early 19th century, and were advancing for several centuries before that. Since about 1970, many of the glaciers have stopped retreating and some are now advancing again. And, frankly, we don't know why.
The other elements of the global-warming scare scenario are predicated on similar oversights. Malaria, claimed as a byproduct of warming, was once common in Michigan and Siberia and remains common in Siberia--mosquitoes don't require tropical warmth. Hurricanes, too, vary on multidecadal time scales; sea-surface temperature is likely to be an important factor. This temperature, itself, varies on multidecadal time scales. However, questions concerning the origin of the relevant sea-surface temperatures and the nature of trends in hurricane intensity are being hotly argued within the profession.
Even among those arguing, there is general agreement that we can't attribute any particular hurricane to global warming. To be sure, there is one exception, Greg Holland of the National Center for Atmospheric Research in Boulder, Colo., who argues that it must be global warming because he can't think of anything else. While arguments like these, based on lassitude, are becoming rather common in climate assessments, such claims, given the primitive state of weather and climate science, are hardly compelling.
A general characteristic of Mr. Gore's approach is to assiduously ignore the fact that the earth and its climate are dynamic; they are always changing even without any external forcing. To treat all change as something to fear is bad enough; to do so in order to exploit that fear is much worse. Regardless, these items are clearly not issues over which debate is ended--at least not in terms of the actual science.
A clearer claim as to what debate has ended is provided by the environmental journalist Gregg Easterbrook. He concludes that the scientific community now agrees that significant warming is occurring, and that there is clear evidence of human influences on the climate system. This is still a most peculiar claim. At some level, it has never been widely contested. Most of the climate community has agreed since 1988 that global mean temperatures have increased on the order of one degree Fahrenheit over the past century, having risen significantly from about 1919 to 1940, decreased between 1940 and the early '70s, increased again until the '90s, and remaining essentially flat since 1998.
There is also little disagreement that levels of carbon dioxide in the atmosphere have risen from about 280 parts per million by volume in the 19th century to about 387 ppmv today. Finally, there has been no question whatever that carbon dioxide is an infrared absorber (i.e., a greenhouse gas--albeit a minor one), and its increase should theoretically contribute to warming. Indeed, if all else were kept equal, the increase in carbon dioxide should have led to somewhat more warming than has been observed, assuming that the small observed increase was in fact due to increasing carbon dioxide rather than a natural fluctuation in the climate system. Although no cause for alarm rests on this issue, there has been an intense effort to claim that the theoretically expected contribution from additional carbon dioxide has actually been detected.
Given that we do not understand the natural internal variability of climate change, this task is currently impossible. Nevertheless there has been a persistent effort to suggest otherwise, and with surprising impact. Thus, although the conflicted state of the affair was accurately presented in the 1996 text of the Intergovernmental Panel on Climate Change, the infamous "summary for policy makers" reported ambiguously that "The balance of evidence suggests a discernible human influence on global climate." This sufficed as the smoking gun for Kyoto.
The next IPCC report again described the problems surrounding what has become known as the attribution issue: that is, to explain what mechanisms are responsible for observed changes in climate. Some deployed the lassitude argument--e.g., we can't think of an alternative--to support human attribution. But the "summary for policy makers" claimed in a manner largely unrelated to the actual text of the report that "In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations."
In a similar vein, the National Academy of Sciences issued a brief (15-page) report responding to questions from the White House. It again enumerated the difficulties with attribution, but again the report was preceded by a front end that ambiguously claimed that "The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability." This was sufficient for CNN's Michelle Mitchell to presciently declare that the report represented a "unanimous decision that global warming is real, is getting worse and is due to man. There is no wiggle room." Well, no.
More recently, a study in the journal Science by the social scientist Nancy Oreskes claimed that a search of the ISI Web of Knowledge Database for the years 1993 to 2003 under the key words "global climate change" produced 928 articles, all of whose abstracts supported what she referred to as the consensus view. A British social scientist, Benny Peiser, checked her procedure and found that only 913 of the 928 articles had abstracts at all, and that only 13 of the remaining 913 explicitly endorsed the so-called consensus view. Several actually opposed it.
Even more recently, the Climate Change Science Program, the Bush administration's coordinating agency for global-warming research, declared it had found "clear evidence of human influences on the climate system." This, for Mr. Easterbrook, meant: "Case closed."
What exactly was this evidence? The models imply that greenhouse warming should impact atmospheric temperatures more than surface temperatures, and yet satellite data showed no warming in the atmosphere since 1979. The report showed that selective corrections to the atmospheric data could lead to some warming, thus reducing the conflict between observations and models descriptions of what greenhouse warming should look like. That, to me, means the case is still very much open.
So what, then, is one to make of this alleged debate? I would suggest at least three points.
First, nonscientists generally do not want to bother with understanding the science. Claims of consensus relieve policy types, environmental advocates and politicians of any need to do so. Such claims also serve to intimidate the public and even scientists--especially those outside the area of climate dynamics. Secondly, given that the question of human attribution largely cannot be resolved, its use in promoting visions of disaster constitutes nothing so much as a bait-and-switch scam. That is an inauspicious beginning to what Mr. Gore claims is not a political issue but a "moral" crusade.
Lastly, there is a clear attempt to establish truth not by scientific methods but by perpetual repetition. An earlier attempt at this was accompanied by tragedy. Perhaps Marx was right. This time around we may have farce--if we're lucky.
Mr. Lindzen is the Alfred P. Sloan Professor of Atmospheric Science at MIT.
Friday, July 6, 2007
This editorial is over a year old, but just as relevant today as it was then. It was originally published in the Wall Street Journal, you can find it here: http://www.opinionjournal.com/extra/?id=110008220
Peter
Climate of Fear Global-warming alarmists intimidate dissenting scientists into silence.
BY RICHARD LINDZEN Wednesday, April 12, 2006 12:01 a.m. EDT
There have been repeated claims that this past year's hurricane activity was another sign of human-induced climate change. Everything from the heat wave in Paris to heavy snows in Buffalo has been blamed on people burning gasoline to fuel their cars, and coal and natural gas to heat, cool and electrify their homes. Yet how can a barely discernible, one-degree increase in the recorded global mean temperature since the late 19th century possibly gain public acceptance as the source of recent weather catastrophes? And how can it translate into unlikely claims about future catastrophes?
The answer has much to do with misunderstanding the science of climate, plus a willingness to debase climate science into a triangle of alarmism. Ambiguous scientific statements about climate are hyped by those with a vested interest in alarm, thus raising the political stakes for policy makers who provide funds for more science research to feed more alarm to increase the political stakes. After all, who puts money into science--whether for AIDS, or space, or climate--where there is nothing really alarming?
Indeed, the success of climate alarmism can be counted in the increased federal spending on climate research from a few hundred million dollars pre-1990 to $1.7 billion today. It can also be seen in heightened spending on solar, wind, hydrogen, ethanol and clean coal technologies, as well as on other energy-investment decisions.
But there is a more sinister side to this feeding frenzy. Scientists who dissent from the alarmism have seen their grant funds disappear, their work derided, and themselves libeled as industry stooges, scientific hacks or worse. Consequently, lies about climate change gain credence even when they fly in the face of the science that supposedly is their basis.
To understand the misconceptions perpetuated about climate science and the climate of intimidation, one needs to grasp some of the complex underlying scientific issues. First, let's start where there is agreement. The public, press and policy makers have been repeatedly told that three claims have widespread scientific support: Global temperature has risen about a degree since the late 19th century; levels of CO2 in the atmosphere have increased by about 30% over the same period; and CO2 should contribute to future warming.
These claims are true. However, what the public fails to grasp is that the claims neither constitute support for alarm nor establish man's responsibility for the small amount of warming that has occurred. In fact, those who make the most outlandish claims of alarm are actually demonstrating skepticism of the very science they say supports them. It isn't just that the alarmists are trumpeting model results that we know must be wrong. It is that they are trumpeting catastrophes that couldn't happen even if the models were right as justifying costly policies to try to prevent global warming.
If the models are correct, global warming reduces the temperature differences between the poles and the equator. When you have less difference in temperature, you have less excitation of extratropical storms, not more. And, in fact, model runs support this conclusion. Alarmists have drawn some support for increased claims of tropical storminess from a casual claim by Sir John Houghton of the U.N.'s Intergovernmental Panel on Climate Change (IPCC) that a warmer world would have more evaporation, with latent heat providing more energy for disturbances.
The problem with this is that the ability of evaporation to drive tropical storms relies not only on temperature but humidity as well, and calls for drier, less humid air. Claims for starkly higher temperatures are based upon there being more humidity, not less--hardly a case for more storminess with global warming.
So how is it that we don't have more scientists speaking up about this junk science? It's my belief that many scientists have been cowed not merely by money but by fear. An example: Earlier this year, Texas Rep. Joe Barton issued letters to paleoclimatologist Michael Mann and some of his co-authors seeking the details behind a taxpayer-funded analysis that claimed the 1990s were likely the warmest decade and 1998 the warmest year in the last millennium.
Mr. Barton's concern was based on the fact that the IPCC had singled out Mr. Mann's work as a means to encourage policy makers to take action. And they did so before his work could be replicated and tested--a task made difficult because Mr. Mann, a key IPCC author, had refused to release the details for analysis. The scientific community's defense of Mr. Mann was, nonetheless, immediate and harsh. The president of the National Academy of Sciences--as well as the American Meteorological Society and the American Geophysical Union--formally protested, saying that Rep. Barton's singling out of a scientist's work smacked of intimidation.
All of which starkly contrasts to the silence of the scientific community when anti-alarmists were in the crosshairs of then-Sen. Al Gore. In 1992, he ran two congressional hearings during which he tried to bully dissenting scientists, including myself, into changing our views and supporting his climate alarmism. Nor did the scientific community complain when Mr. Gore, as vice president, tried to enlist Ted Koppel in a witch hunt to discredit anti-alarmist scientists--a request that Mr. Koppel deemed publicly inappropriate. And they were mum when subsequent articles and books by Ross Gelbspan libelously labeled scientists who differed with Mr. Gore as stooges of the fossil-fuel industry.
Sadly, this is only the tip of a non-melting iceberg. In Europe, Henk Tennekes was dismissed as research director of the Royal Dutch Meteorological Society after questioning the scientific underpinnings of global warming. Aksel Winn-Nielsen, former director of the U.N.'s World Meteorological Organization, was tarred by Bert Bolin, first head of the IPCC, as a tool of the coal industry for questioning climate alarmism. Respected Italian professors Alfonso Sutera and Antonio Speranza disappeared from the debate in 1991, apparently losing climate-research funding for raising questions.
And then there are the peculiar standards in place in scientific journals for articles submitted by those who raise questions about accepted climate wisdom. At Science and Nature, such papers are commonly refused without review as being without interest. However, even when such papers are published, standards shift.
When I, with some colleagues at NASA, attempted to determine how clouds behave under varying temperatures, we discovered what we called an "Iris Effect," wherein upper-level cirrus clouds contracted with increased temperature, providing a very strong negative climate feedback sufficient to greatly reduce the response to increasing CO2. Normally, criticism of papers appears in the form of letters to the journal to which the original authors can respond immediately.
However, in this case (and others) a flurry of hastily prepared papers appeared, claiming errors in our study, with our responses delayed months and longer. The delay permitted our paper to be commonly referred to as "discredited." Indeed, there is a strange reluctance to actually find out how climate really behaves. In 2003, when the draft of the U.S. National Climate Plan urged a high priority for improving our knowledge of climate sensitivity, the National Research Council instead urged support to look at the impacts of the warming--not whether it would actually happen.
Alarm rather than genuine scientific curiosity, it appears, is essential to maintaining funding. And only the most senior scientists today can stand up against this alarmist gale, and defy the iron triangle of climate scientists, advocates and policymakers.
Mr. Lindzen is Alfred P. Sloan Professor of Atmospheric Science at MIT.
Peter
Climate of Fear Global-warming alarmists intimidate dissenting scientists into silence.
BY RICHARD LINDZEN Wednesday, April 12, 2006 12:01 a.m. EDT
There have been repeated claims that this past year's hurricane activity was another sign of human-induced climate change. Everything from the heat wave in Paris to heavy snows in Buffalo has been blamed on people burning gasoline to fuel their cars, and coal and natural gas to heat, cool and electrify their homes. Yet how can a barely discernible, one-degree increase in the recorded global mean temperature since the late 19th century possibly gain public acceptance as the source of recent weather catastrophes? And how can it translate into unlikely claims about future catastrophes?
The answer has much to do with misunderstanding the science of climate, plus a willingness to debase climate science into a triangle of alarmism. Ambiguous scientific statements about climate are hyped by those with a vested interest in alarm, thus raising the political stakes for policy makers who provide funds for more science research to feed more alarm to increase the political stakes. After all, who puts money into science--whether for AIDS, or space, or climate--where there is nothing really alarming?
Indeed, the success of climate alarmism can be counted in the increased federal spending on climate research from a few hundred million dollars pre-1990 to $1.7 billion today. It can also be seen in heightened spending on solar, wind, hydrogen, ethanol and clean coal technologies, as well as on other energy-investment decisions.
But there is a more sinister side to this feeding frenzy. Scientists who dissent from the alarmism have seen their grant funds disappear, their work derided, and themselves libeled as industry stooges, scientific hacks or worse. Consequently, lies about climate change gain credence even when they fly in the face of the science that supposedly is their basis.
To understand the misconceptions perpetuated about climate science and the climate of intimidation, one needs to grasp some of the complex underlying scientific issues. First, let's start where there is agreement. The public, press and policy makers have been repeatedly told that three claims have widespread scientific support: Global temperature has risen about a degree since the late 19th century; levels of CO2 in the atmosphere have increased by about 30% over the same period; and CO2 should contribute to future warming.
These claims are true. However, what the public fails to grasp is that the claims neither constitute support for alarm nor establish man's responsibility for the small amount of warming that has occurred. In fact, those who make the most outlandish claims of alarm are actually demonstrating skepticism of the very science they say supports them. It isn't just that the alarmists are trumpeting model results that we know must be wrong. It is that they are trumpeting catastrophes that couldn't happen even if the models were right as justifying costly policies to try to prevent global warming.
If the models are correct, global warming reduces the temperature differences between the poles and the equator. When you have less difference in temperature, you have less excitation of extratropical storms, not more. And, in fact, model runs support this conclusion. Alarmists have drawn some support for increased claims of tropical storminess from a casual claim by Sir John Houghton of the U.N.'s Intergovernmental Panel on Climate Change (IPCC) that a warmer world would have more evaporation, with latent heat providing more energy for disturbances.
The problem with this is that the ability of evaporation to drive tropical storms relies not only on temperature but humidity as well, and calls for drier, less humid air. Claims for starkly higher temperatures are based upon there being more humidity, not less--hardly a case for more storminess with global warming.
So how is it that we don't have more scientists speaking up about this junk science? It's my belief that many scientists have been cowed not merely by money but by fear. An example: Earlier this year, Texas Rep. Joe Barton issued letters to paleoclimatologist Michael Mann and some of his co-authors seeking the details behind a taxpayer-funded analysis that claimed the 1990s were likely the warmest decade and 1998 the warmest year in the last millennium.
Mr. Barton's concern was based on the fact that the IPCC had singled out Mr. Mann's work as a means to encourage policy makers to take action. And they did so before his work could be replicated and tested--a task made difficult because Mr. Mann, a key IPCC author, had refused to release the details for analysis. The scientific community's defense of Mr. Mann was, nonetheless, immediate and harsh. The president of the National Academy of Sciences--as well as the American Meteorological Society and the American Geophysical Union--formally protested, saying that Rep. Barton's singling out of a scientist's work smacked of intimidation.
All of which starkly contrasts to the silence of the scientific community when anti-alarmists were in the crosshairs of then-Sen. Al Gore. In 1992, he ran two congressional hearings during which he tried to bully dissenting scientists, including myself, into changing our views and supporting his climate alarmism. Nor did the scientific community complain when Mr. Gore, as vice president, tried to enlist Ted Koppel in a witch hunt to discredit anti-alarmist scientists--a request that Mr. Koppel deemed publicly inappropriate. And they were mum when subsequent articles and books by Ross Gelbspan libelously labeled scientists who differed with Mr. Gore as stooges of the fossil-fuel industry.
Sadly, this is only the tip of a non-melting iceberg. In Europe, Henk Tennekes was dismissed as research director of the Royal Dutch Meteorological Society after questioning the scientific underpinnings of global warming. Aksel Winn-Nielsen, former director of the U.N.'s World Meteorological Organization, was tarred by Bert Bolin, first head of the IPCC, as a tool of the coal industry for questioning climate alarmism. Respected Italian professors Alfonso Sutera and Antonio Speranza disappeared from the debate in 1991, apparently losing climate-research funding for raising questions.
And then there are the peculiar standards in place in scientific journals for articles submitted by those who raise questions about accepted climate wisdom. At Science and Nature, such papers are commonly refused without review as being without interest. However, even when such papers are published, standards shift.
When I, with some colleagues at NASA, attempted to determine how clouds behave under varying temperatures, we discovered what we called an "Iris Effect," wherein upper-level cirrus clouds contracted with increased temperature, providing a very strong negative climate feedback sufficient to greatly reduce the response to increasing CO2. Normally, criticism of papers appears in the form of letters to the journal to which the original authors can respond immediately.
However, in this case (and others) a flurry of hastily prepared papers appeared, claiming errors in our study, with our responses delayed months and longer. The delay permitted our paper to be commonly referred to as "discredited." Indeed, there is a strange reluctance to actually find out how climate really behaves. In 2003, when the draft of the U.S. National Climate Plan urged a high priority for improving our knowledge of climate sensitivity, the National Research Council instead urged support to look at the impacts of the warming--not whether it would actually happen.
Alarm rather than genuine scientific curiosity, it appears, is essential to maintaining funding. And only the most senior scientists today can stand up against this alarmist gale, and defy the iron triangle of climate scientists, advocates and policymakers.
Mr. Lindzen is Alfred P. Sloan Professor of Atmospheric Science at MIT.
Wednesday, June 13, 2007
Is There A Basis For Global Warming Alarm? by Richard S. Lindzen
1
Is there a basis for global warming alarm?
Richard S. Lindzen
Alfred P. Sloan Professor of Atmospheric Science
Massachusetts Institute of Technology
Yale Center for the Study of Globalization
October 21, 2005
These slides are available as a pdffile from rlindzen@mit.edu
2
The reality of global warming is frequently attested to by reference to a scientific consensus:
Tony Blair: "The overwhelming view of experts is that climate change, to a greater or lesser extent, is man-made, and, without action, will get worse."
Elizabeth Kolbertin New Yorker: "All that the theory of global warming says is that if you increase the concentration of greenhouse gases in the atmosphere, you will also increase the earth's average temperature. It's indisputable that we have increased greenhouse-gas concentrations in the air as a result of human activity, and it's also indisputable that over the lastfew decades average global temperatures have gone up."
3
These references fail to note that there are many sources of climate change, and that profound climate change occurred many times both before and after man appeared on earth.
Given the ubiquity of climate change, it is implausible that allchange is for the worse.
Moreover, the coincidence of increasing CO2and the small warming over the past century hardly establishes causality.
Nevertheless, for the most part I do not personally disagree with the Consensus (though the absence of any quantitiveconsiderations should be disturbing).Indeed, I know of no serious split, and suspect that the claim that there is opposition to this consensus amounts to no more than setting up a straw man to scoff at.
4
However, I believe that people are being led astray by the suggestion this agreement constitutes support for alarm.
5
What is truly agreed (albeit with some controversy)
1. The global mean surface temperature is always changing. Overthe past 60 years, it has both decreased and increased. For the past century, it has probably increased by about 0.6 ±0.15degrees Centigrade (C). That is to say, we have had some global mean warming.
2. CO2is a greenhouse gas and its increase should contribute to warming. It is, in fact, increasing, and a doubling would increase the greenhouse effect (mainly due to water vapor and clouds) by about 2%.
3. There is good evidence that man has been responsible for the recent increase in CO2, though climate itself (as well as other natural phenomena) canalso cause changes in CO2.
Let us refer to the above as the basic agreement. Consensus generally refers to these three relatively trivial points.
6
Is there any reason to consider this basic agreement as being alarming?
Relatedly, is there any objective basis for considering the approximate 0.6C increase in global mean surface temperature to be large or small.
The answer to both questions depends on whether 0.6C is larger or smaller than what we might have expected.
A useful approach to this question is to determine how the current level of man made climate forcing compares with what we would have were CO2to be doubled (a common reference level for GCM calculations).
7
In terms of climate forcing, greenhouse gases added to the atmosphere through mans activities since the late 19thCentury have already produced three-quartersof the radiative forcing that we expect from a doubling of CO2. The main reasons for this are
1) CO2is not the only anthropogenic greenhouse gas -others like methane also contribute; and
2) the impact of CO2is nonlinear in the sense that each added unit contributes less than its predecessor. For example, if doublingCO2from its value in the late 19th Century (about 290 parts per million by volume or ppmv) to double this (i.e., 580 ppmv) causes a 2% increase in radiative forcing, then to obtain another 2% increase in radiative forcing we must increase CO2by an additional 580 ppmvrather than by another 290 ppmv. At present, the concentration of CO2is about 380 ppmv.
It should be stressed that we are interested in climate forcing,and not simply levels of CO2.
8 200400600800100012001400CO2 (ppmv)024681012Percentage increase in radiative forcingLinearLogarithmicThe CO2forcing follows the logarithmic rather than the linear curve. Note that the logarithmic curve rises ever more slowly as the CO2increases.The easiest way to understand this is to consider adding thin layers of paint to a pane of glass. The first layer cuts out much of the light, the next layer cuts out more, but subsequent layers do less and less because the painted pane is already essentially opaque.
9
This brings us, finally, to the issue of climate models. Essential to alarm is the fact that most current climate models predict a response to a doubling of CO2of about 4C (which is much larger than what one expects the simple doubling of CO2to produce: ie, about 1C). The reason for this is that in these models, the most important greenhouse substances, water vapor and clouds, act in such a way as to greatly amplify the response to anthropogenic greenhouse gases alone (ie, they act as what are called large positive feedbacks). However, as all assessments of the Intergovernmental Panel on Climate Change (IPCC) have stated (at least in the text –though not in the Summaries for Policymakers), the models simply fail to get clouds and water vapor right. We know this because in official model intercomparisons, all models fail miserably to replicate observed distributions of cloud cover. Thus, the model predictions are critically dependent on features that we know must be wrong.
10
Here we see that treatment of clouds involves errors an order of
magnitude greater than the forcing from a doubling of CO2
11
Let me summarize the main points thus far:
1. It is NOT the level of CO2that is important, but rather the impact of man made greenhouse gases on climate.
2. Although we are far from the benchmark of doubled CO2, climate forcing is already about 3/4 of what we expect from such a doubling.
3. Even if we attribute all warming over the past century to man made greenhouse gases (which we have no basis for doing), the observed warming is only about 1/3-1/6 of what models project.
12
We are logically led to two possibilities:
1. Our models are greatly overestimating the sensitivity of climate to man made greenhouse gases, or
2. The models are correct, but there is some unknown process that has cancelled most of the warming.
Note that calling the unknown process "aerosols"does not change this statement since aerosols and their impact are unknown to a factor of ten or more; indeed, even the sign is in doubt.
In arguing for climate alarmism, we are choosing the second possibility. Moreover, we are assuming that the unknown cancellation will soon cease.
13
How is the second possibility supported?
The IPCC TAR made use of a peculiar exercise in curve fitting using results from the Hadley Centre.
14 15 In the first, we are shown an observed temperature record (without error bars), and the results of four model runs with so-called natural forcing for the period 1860-2000. There is a small spread in the model runs (which presumably displays model uncertainty –it most assuredly does not represent internal variability). In any event, the models look roughly like the observations until the last 30 years. In the first, we are shown an observed temperature record (without error bars), and the results of four model runs with so-called natural forcing for the period 1860-2000. There is a small spread in the model runs (which presumably displays model uncertainty –it most assuredly does not represent internal variability). In any event, the models look roughly like the observations until the last 30 years.
16 We are then shown a second diagram where the observed curve is reproduced, and the four models are run with anthropogenic forcing. Here we see rough agreement over the last 30 years, and poorer agreement in the earlier period. We are then shown a second diagram where the observed curve is reproduced, and the four models are run with anthropogenic forcing. Here we see rough agreement over the last 30 years, and poorer agreement in the earlier period.
17 Finally, we are shown the observations and the model runs with both natural and anthropogenic forcing, and, voila, there is rough agreement over the whole record. It should be noted that the models used had a relatively low sensitivity to a doubling of CO2of about 2.5C. Finally, we are shown the observations and the model runs with both natural and anthropogenic forcing, and, voila, there is rough agreement over the whole record. It should be noted that the models used had a relatively low sensitivity to a doubling of CO2of about 2.5C.
18
In order to know what to make of this exercise, one must know exactly what was done.
19 The natural forcing consisted in volcanoes and solar variability. Prior to the Pinatubo eruption in 1991, the radiative impact of volcanoes was not well measured, and estimates vary by about a factor of 3. Solar forcing is essentially unknown. Thus, natural forcing is, in essence, adjustable. The natural forcing consisted in volcanoes and solar variability. Prior to the Pinatubo eruption in 1991, the radiative impact of volcanoes was not well measured, and estimates vary by about a factor of 3. Solar forcing is essentially unknown. Thus, natural forcing is, in essence, adjustable.
20 Anthropogenic forcing includes not only anthropogenic greenhouse gases, but also aerosols that act to cancel warming (in the Hadley Centre results, aerosols and other factors cancelled two thirds of the greenhouse forcing). Unfortunately, the properties of aerosols are largely unknown. In the present instance, therefore, aerosols constitute simply another adjustable parameter (indeed, both its magnitude and its time history are adjustable). Anthropogenic forcing includes not only anthropogenic greenhouse gases, but also aerosols that act to cancel warming (in the Hadley Centre results, aerosols and other factors cancelled two thirds of the greenhouse forcing). Unfortunately, the properties of aerosols are largely unknown. In the present instance, therefore, aerosols constitute simply another adjustable parameter (indeed, both its magnitude and its time history are adjustable).
21 Science, 2003This was remarked upon in a recent paper in Science, wherein it was noted that the uncertainty was so great that estimating aerosol properties by tuning them to optimize agreement between models and observations (referred to as an inverse method) was probably as good as any other method, but that the use of such estimates to then test the models constituted a circular procedure. This was remarked upon in a recent paper in Science, wherein it was noted that the uncertainty was so great that estimating aerosol properties by tuning them to optimize agreement between models and observations (referred to as an inverse method) was probably as good as any other method, but that the use of such estimates to then test the models constituted a circular procedure. The choice of models with relatively low sensitivity, allowed adjustments that were not so extreme. The choice of models with relatively low sensitivity, allowed adjustments that were not so extreme.
22
New uncertainties are always entering the aerosol picture. Some are quite bizarre.
23
Of course this is the beauty of the global warming issue for many scientists. The issue deals with such small climate forcing andsmall temperature changes that it permits scientists to argue that everything and anything is important for climate.
24
In brief, the defense of the models starts by assuming the modelis correct. One then attributes differences between the model behavior in the absence of external forcing, and observed changes in ‘global mean temperature’to external forcing. Next one introduces ‘natural’forcing and tries to obtain a ‘best fit’to observations. If, finally, one is able to remove remaining discrepancies by introducing ‘anthropogenic’forcing, we assert that the attribution of part of the observed change to the greenhouse component of ‘anthropogenic’forcing must be correct.
Of course, model internal variability is not correct, and ‘anthropogenic’forcing includes not only CO2but also aerosols, and the latter are unknown to a factor of 10-20 (and perhaps even sign). Finally, we have little quantitative knowledge of ‘natural’forcing so this too is adjustable. Note that the Hadley Centre acknowledges that the "aerosols"cancelled most of the forcing from CO2.
25
Yet, the ‘argument’I have just presented is the basis for all popular claims that scientists now ‘believe’that man is responsible for much of the observed warming!
It would appear that the current role of the scientist in the global warming issue is simply to defend the ‘possibility’of ominous predictions so as to justify his ‘belief.’
26
To be fair to the authors of Chapter 12 of the IPCC Third Scientific Assessment here is what they provided for the draft statement ofthe Policymakers Summary: From the body of evidence since IPCC (1996), we conclude that there has been a discernible human influence on global climate. Studies are beginning to separate the contributions to observed climate change attributable to individual external influences, both anthropogenic and natural. This work suggests that anthropogenic greenhouse gases are a substantial contributor to the observed warming, especially over the past 30years. However, the accuracy of these estimates continues to be limited by uncertainties in estimates of internal variability, natural and anthropogenic forcing, and the climate response to external forcing.
27
This statement is not too bad –especially the last sentence. To be sure, the model dependence of the results is not emphasized, butthe statement is vastly more honest than what the Summary for Policymakers in the IPCC’sThird Assessment Report ultimately presented:
In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.
28
In point of fact, the impact of man remains indiscernible simplybecause the signal is too small compared to the natural noise. Claims that the current temperatures are ‘record breaking’or ‘unprecedented’, however questionable or misleading, simply serve to obscure the fact that the observed warming is too smallcompared to what models suggest. Even the fact that the oceans’heat capacity leads to a delay in the response of the surface does not alter this conclusion.
29
Moreover, the fact that we already have three quarters of the climate forcing expected from a doubling of CO2means that if one truly believes the models, then we have long since passed the point where mitigation is a viable strategy. What remains is to maximize our ability to adapt.
30
That the promotion of alarm does not follow from the science, isclearly illustrated by the following example.
According to any textbook on dynamic meteorology, one may reasonably conclude that in a warmer world, extratropicalstorminess and weather variability will actually decrease. The reasoning is as follows. Judging by historical climate change, changes are greater in high latitudesthan in the tropics. Thus, in a warmer world, we would expect that the temperature difference between high and low latitudes would diminish. However, it is precisely this difference that gives rise to extratropicallarge-scale weather disturbances. Moreover, when in Boston on a winter day we experience unusual warmth, it is because the wind is blowing from the south. Similarly, when we experience unusual cold, it is generally because the wind is blowing from the north. The possible extent of these extremes is, not surprisingly, determined by how warm low latitudes are and how cold high latitudes are. Given that we expect that high latitudes will warm much more than low latitudes in a warmer climate, the differenceis expected to diminish, leading to less variance.
31
Nevertheless, we are told by advocates and the media that exactly the opposite is the case, and that, moreover, the modelspredict this (which, to their credit, they do not) and that the basic agreementdiscussed earlier signifies scientific agreement on this matter as well. Clearly more storms and greater extremes are regarded as more alarming than the opposite. Thus, the opposite of our current understanding is invoked in order to promote public concern. The crucial point here is that once the principle of consensus is accepted, agreement on anything is taken to infer agreement on everything advocates wish to claim.
32
At this point, it is doubtful that we are even dealing with a serious problem. If this is correct, then there is no policy addressingthis non-problem that would be cost-effective. Even if we believe the problem to be serious, we have already reached the levels of climate forcing that have been claimed to be serious. However, when it comes to Kyoto, the situation is even worse. Here, there is widespread and even rigorous scientific agreement that complete adherence to the Kyoto Agreement would have no discernible impact on climate regardless of what one believes about climate. Thus, the theme of this meeting is, at least onthis count, appropriate.
33
What about the first possibility: namely that the models on which we are basing our alarm are much too sensitive? Not only is this the possibility that scientists would normally have preferred on the basis of Occam’s famous razor, but it is also a possibility for which there is substantial support.
I will focus on one line of this evidence: tropical warming in the 90's has been associated with much greater outgoing long wave radiation than models produce. This discrepancy points toward the absence of a strong negative feedback in current models.
The discrepancy has been confirmed by at least four independent groups.
34
Chen, J., B.E. Carlson, and A.D. Del Genio, 2002: Evidence for strengthening of the tropical general circulation in the 1990s. Science, 295, 838-841.
Del Genio, A. D., and W. Kovari, 2002: Climatic properties of tropical precipitating convection under varying environmental
conditions. J. Climate, 15, 2597–2615.
Wielicki, B.A., T. Wong, et al, 2002: Evidence for large decadal variability in the tropical mean radiative energy budget. Science, 295, 841-844.
Lin, B., T. Wong, B. Wielicki, and Y. Hu, 2004: Examination of the decadal tropical mean ERBS nonscannerradiation data for the iris hypothesis. J. Climate, 17, 1239-1246.
Cess, R.D. and P.M. Udelhofen, 2003: Climate change during 1985–1999: Cloud interactions determined from satellite measurements. Geophys. Res. Ltrs., 30, No. 1, 1019, doi:10.1029/2002GL016128.
Clement, A.C. and B. Soden(2005) The sensitivity of the tropical-mean radiation budget. J. Clim., 18, 3189-3203.
35
The preceding papers attempted to either attribute the discrepancy to circulation changes or to ‘unknown’cloud properties –except for the last paper.
Clement and Soden(2005) showed that changes in dynamics could not produce changes averaged over the tropics. They showed this using 4 separate models, but it had been shown theoretically in
Chou, M.-D. and R.S. Lindzen (2004) Comments on "Examination of the Decadal Tropical Mean ERBS NonscannerRadiation Data for the Iris Hypothesis". J. Clim.18, 2123-2127.
Clement and Sodenalso showed that the discrepancy could be resolved by allowing convective precipitation efficiency to increase with surface temperature.
36
Such a dependence is at the heart of the iris effect which was first found by
R.S. Lindzen, M.-D. Chou, and A.Y. Hou(2001) Does the Earth have an adaptive infrared iris? Bull. Amer. Met. Soc.82, 417-432.
and was theoretically predicted by
Sun, D-Z. and R.S. Lindzen (1993) Distribution of tropical troposphericwater vapor. J. Atmos. Sci., 50, 1643-1660.
In LCH, we attempted to do examine how tropical clouds responded to changing surface temperature, and found that existing satellite data was only marginally capable of dealing with this issue. The results, however, suggested that there were strong negative feedbacks --counter to what models suggest. It was moreover, easy to show that models in no way replicated the cloud behavior that was observed.
37
Ground based radar allows the almost continuous measurement of precipitation and the separation of convective precipitation from stratiformprecipitation. In the tropics, both types of precipitation originate in condensation within cumulus towers. However, condensation that does not form precipitation is carried aloft as ice which is detrained to form cirrus from which the condensate eventually falls as stratiformprecipitation.
Precipitation efficiency is given by the relation
It now turns out that the rigorous measurement of precipitation can be done with ground based radar.convective precipitationconvective precipitation + stratiform precipitatione=
38 Using data from Kwajalein Atoll in the western Pacific, we were able to study how evaries with sea surface temperature.
39
In addition, the Kwajalein radar allows one to explicitly look at the area of stratiformrain per unit of convective mass flux.
40
We see that eincreases about 7.1% per degree C increase in SST (compared with 7.5% estimated by Sun and Lindzen, 1993), and that this increase is associated with a decrease in normalized stratiformarea of about 25% per degree C (which is a bit larger than what was estimated from space observations by Lindzen, Chou and Hou, 2001).
This basically confirms the iris effect, and the fact that models have greatly exaggerated climate sensitivity because, in contrast to models, nature, itself, acts to limit rather than exaggerate the influence of added greenhouse gases.
41
The primary implication is that for over 25 years, we have based not only our worst case scenarios but even our best case scenarios on model exaggeration.
As far as I can tell, the main question we ought to be confronting is how long the momentum generated by this issue will prevent us from seeing that it has been an illusion based on model error.
What is the implication of these simple results?
42
In the mean time, we can continue to play our parts in the modern version of "The Emperor’s New Clothes."Our descendents will be amused for generations to come.
Is there a basis for global warming alarm?
Richard S. Lindzen
Alfred P. Sloan Professor of Atmospheric Science
Massachusetts Institute of Technology
Yale Center for the Study of Globalization
October 21, 2005
These slides are available as a pdffile from rlindzen@mit.edu
2
The reality of global warming is frequently attested to by reference to a scientific consensus:
Tony Blair: "The overwhelming view of experts is that climate change, to a greater or lesser extent, is man-made, and, without action, will get worse."
Elizabeth Kolbertin New Yorker: "All that the theory of global warming says is that if you increase the concentration of greenhouse gases in the atmosphere, you will also increase the earth's average temperature. It's indisputable that we have increased greenhouse-gas concentrations in the air as a result of human activity, and it's also indisputable that over the lastfew decades average global temperatures have gone up."
3
These references fail to note that there are many sources of climate change, and that profound climate change occurred many times both before and after man appeared on earth.
Given the ubiquity of climate change, it is implausible that allchange is for the worse.
Moreover, the coincidence of increasing CO2and the small warming over the past century hardly establishes causality.
Nevertheless, for the most part I do not personally disagree with the Consensus (though the absence of any quantitiveconsiderations should be disturbing).Indeed, I know of no serious split, and suspect that the claim that there is opposition to this consensus amounts to no more than setting up a straw man to scoff at.
4
However, I believe that people are being led astray by the suggestion this agreement constitutes support for alarm.
5
What is truly agreed (albeit with some controversy)
1. The global mean surface temperature is always changing. Overthe past 60 years, it has both decreased and increased. For the past century, it has probably increased by about 0.6 ±0.15degrees Centigrade (C). That is to say, we have had some global mean warming.
2. CO2is a greenhouse gas and its increase should contribute to warming. It is, in fact, increasing, and a doubling would increase the greenhouse effect (mainly due to water vapor and clouds) by about 2%.
3. There is good evidence that man has been responsible for the recent increase in CO2, though climate itself (as well as other natural phenomena) canalso cause changes in CO2.
Let us refer to the above as the basic agreement. Consensus generally refers to these three relatively trivial points.
6
Is there any reason to consider this basic agreement as being alarming?
Relatedly, is there any objective basis for considering the approximate 0.6C increase in global mean surface temperature to be large or small.
The answer to both questions depends on whether 0.6C is larger or smaller than what we might have expected.
A useful approach to this question is to determine how the current level of man made climate forcing compares with what we would have were CO2to be doubled (a common reference level for GCM calculations).
7
In terms of climate forcing, greenhouse gases added to the atmosphere through mans activities since the late 19thCentury have already produced three-quartersof the radiative forcing that we expect from a doubling of CO2. The main reasons for this are
1) CO2is not the only anthropogenic greenhouse gas -others like methane also contribute; and
2) the impact of CO2is nonlinear in the sense that each added unit contributes less than its predecessor. For example, if doublingCO2from its value in the late 19th Century (about 290 parts per million by volume or ppmv) to double this (i.e., 580 ppmv) causes a 2% increase in radiative forcing, then to obtain another 2% increase in radiative forcing we must increase CO2by an additional 580 ppmvrather than by another 290 ppmv. At present, the concentration of CO2is about 380 ppmv.
It should be stressed that we are interested in climate forcing,and not simply levels of CO2.
8 200400600800100012001400CO2 (ppmv)024681012Percentage increase in radiative forcingLinearLogarithmicThe CO2forcing follows the logarithmic rather than the linear curve. Note that the logarithmic curve rises ever more slowly as the CO2increases.The easiest way to understand this is to consider adding thin layers of paint to a pane of glass. The first layer cuts out much of the light, the next layer cuts out more, but subsequent layers do less and less because the painted pane is already essentially opaque.
9
This brings us, finally, to the issue of climate models. Essential to alarm is the fact that most current climate models predict a response to a doubling of CO2of about 4C (which is much larger than what one expects the simple doubling of CO2to produce: ie, about 1C). The reason for this is that in these models, the most important greenhouse substances, water vapor and clouds, act in such a way as to greatly amplify the response to anthropogenic greenhouse gases alone (ie, they act as what are called large positive feedbacks). However, as all assessments of the Intergovernmental Panel on Climate Change (IPCC) have stated (at least in the text –though not in the Summaries for Policymakers), the models simply fail to get clouds and water vapor right. We know this because in official model intercomparisons, all models fail miserably to replicate observed distributions of cloud cover. Thus, the model predictions are critically dependent on features that we know must be wrong.
10
Here we see that treatment of clouds involves errors an order of
magnitude greater than the forcing from a doubling of CO2
11
Let me summarize the main points thus far:
1. It is NOT the level of CO2that is important, but rather the impact of man made greenhouse gases on climate.
2. Although we are far from the benchmark of doubled CO2, climate forcing is already about 3/4 of what we expect from such a doubling.
3. Even if we attribute all warming over the past century to man made greenhouse gases (which we have no basis for doing), the observed warming is only about 1/3-1/6 of what models project.
12
We are logically led to two possibilities:
1. Our models are greatly overestimating the sensitivity of climate to man made greenhouse gases, or
2. The models are correct, but there is some unknown process that has cancelled most of the warming.
Note that calling the unknown process "aerosols"does not change this statement since aerosols and their impact are unknown to a factor of ten or more; indeed, even the sign is in doubt.
In arguing for climate alarmism, we are choosing the second possibility. Moreover, we are assuming that the unknown cancellation will soon cease.
13
How is the second possibility supported?
The IPCC TAR made use of a peculiar exercise in curve fitting using results from the Hadley Centre.
14 15 In the first, we are shown an observed temperature record (without error bars), and the results of four model runs with so-called natural forcing for the period 1860-2000. There is a small spread in the model runs (which presumably displays model uncertainty –it most assuredly does not represent internal variability). In any event, the models look roughly like the observations until the last 30 years. In the first, we are shown an observed temperature record (without error bars), and the results of four model runs with so-called natural forcing for the period 1860-2000. There is a small spread in the model runs (which presumably displays model uncertainty –it most assuredly does not represent internal variability). In any event, the models look roughly like the observations until the last 30 years.
16 We are then shown a second diagram where the observed curve is reproduced, and the four models are run with anthropogenic forcing. Here we see rough agreement over the last 30 years, and poorer agreement in the earlier period. We are then shown a second diagram where the observed curve is reproduced, and the four models are run with anthropogenic forcing. Here we see rough agreement over the last 30 years, and poorer agreement in the earlier period.
17 Finally, we are shown the observations and the model runs with both natural and anthropogenic forcing, and, voila, there is rough agreement over the whole record. It should be noted that the models used had a relatively low sensitivity to a doubling of CO2of about 2.5C. Finally, we are shown the observations and the model runs with both natural and anthropogenic forcing, and, voila, there is rough agreement over the whole record. It should be noted that the models used had a relatively low sensitivity to a doubling of CO2of about 2.5C.
18
In order to know what to make of this exercise, one must know exactly what was done.
19 The natural forcing consisted in volcanoes and solar variability. Prior to the Pinatubo eruption in 1991, the radiative impact of volcanoes was not well measured, and estimates vary by about a factor of 3. Solar forcing is essentially unknown. Thus, natural forcing is, in essence, adjustable. The natural forcing consisted in volcanoes and solar variability. Prior to the Pinatubo eruption in 1991, the radiative impact of volcanoes was not well measured, and estimates vary by about a factor of 3. Solar forcing is essentially unknown. Thus, natural forcing is, in essence, adjustable.
20 Anthropogenic forcing includes not only anthropogenic greenhouse gases, but also aerosols that act to cancel warming (in the Hadley Centre results, aerosols and other factors cancelled two thirds of the greenhouse forcing). Unfortunately, the properties of aerosols are largely unknown. In the present instance, therefore, aerosols constitute simply another adjustable parameter (indeed, both its magnitude and its time history are adjustable). Anthropogenic forcing includes not only anthropogenic greenhouse gases, but also aerosols that act to cancel warming (in the Hadley Centre results, aerosols and other factors cancelled two thirds of the greenhouse forcing). Unfortunately, the properties of aerosols are largely unknown. In the present instance, therefore, aerosols constitute simply another adjustable parameter (indeed, both its magnitude and its time history are adjustable).
21 Science, 2003This was remarked upon in a recent paper in Science, wherein it was noted that the uncertainty was so great that estimating aerosol properties by tuning them to optimize agreement between models and observations (referred to as an inverse method) was probably as good as any other method, but that the use of such estimates to then test the models constituted a circular procedure. This was remarked upon in a recent paper in Science, wherein it was noted that the uncertainty was so great that estimating aerosol properties by tuning them to optimize agreement between models and observations (referred to as an inverse method) was probably as good as any other method, but that the use of such estimates to then test the models constituted a circular procedure. The choice of models with relatively low sensitivity, allowed adjustments that were not so extreme. The choice of models with relatively low sensitivity, allowed adjustments that were not so extreme.
22
New uncertainties are always entering the aerosol picture. Some are quite bizarre.
23
Of course this is the beauty of the global warming issue for many scientists. The issue deals with such small climate forcing andsmall temperature changes that it permits scientists to argue that everything and anything is important for climate.
24
In brief, the defense of the models starts by assuming the modelis correct. One then attributes differences between the model behavior in the absence of external forcing, and observed changes in ‘global mean temperature’to external forcing. Next one introduces ‘natural’forcing and tries to obtain a ‘best fit’to observations. If, finally, one is able to remove remaining discrepancies by introducing ‘anthropogenic’forcing, we assert that the attribution of part of the observed change to the greenhouse component of ‘anthropogenic’forcing must be correct.
Of course, model internal variability is not correct, and ‘anthropogenic’forcing includes not only CO2but also aerosols, and the latter are unknown to a factor of 10-20 (and perhaps even sign). Finally, we have little quantitative knowledge of ‘natural’forcing so this too is adjustable. Note that the Hadley Centre acknowledges that the "aerosols"cancelled most of the forcing from CO2.
25
Yet, the ‘argument’I have just presented is the basis for all popular claims that scientists now ‘believe’that man is responsible for much of the observed warming!
It would appear that the current role of the scientist in the global warming issue is simply to defend the ‘possibility’of ominous predictions so as to justify his ‘belief.’
26
To be fair to the authors of Chapter 12 of the IPCC Third Scientific Assessment here is what they provided for the draft statement ofthe Policymakers Summary: From the body of evidence since IPCC (1996), we conclude that there has been a discernible human influence on global climate. Studies are beginning to separate the contributions to observed climate change attributable to individual external influences, both anthropogenic and natural. This work suggests that anthropogenic greenhouse gases are a substantial contributor to the observed warming, especially over the past 30years. However, the accuracy of these estimates continues to be limited by uncertainties in estimates of internal variability, natural and anthropogenic forcing, and the climate response to external forcing.
27
This statement is not too bad –especially the last sentence. To be sure, the model dependence of the results is not emphasized, butthe statement is vastly more honest than what the Summary for Policymakers in the IPCC’sThird Assessment Report ultimately presented:
In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations.
28
In point of fact, the impact of man remains indiscernible simplybecause the signal is too small compared to the natural noise. Claims that the current temperatures are ‘record breaking’or ‘unprecedented’, however questionable or misleading, simply serve to obscure the fact that the observed warming is too smallcompared to what models suggest. Even the fact that the oceans’heat capacity leads to a delay in the response of the surface does not alter this conclusion.
29
Moreover, the fact that we already have three quarters of the climate forcing expected from a doubling of CO2means that if one truly believes the models, then we have long since passed the point where mitigation is a viable strategy. What remains is to maximize our ability to adapt.
30
That the promotion of alarm does not follow from the science, isclearly illustrated by the following example.
According to any textbook on dynamic meteorology, one may reasonably conclude that in a warmer world, extratropicalstorminess and weather variability will actually decrease. The reasoning is as follows. Judging by historical climate change, changes are greater in high latitudesthan in the tropics. Thus, in a warmer world, we would expect that the temperature difference between high and low latitudes would diminish. However, it is precisely this difference that gives rise to extratropicallarge-scale weather disturbances. Moreover, when in Boston on a winter day we experience unusual warmth, it is because the wind is blowing from the south. Similarly, when we experience unusual cold, it is generally because the wind is blowing from the north. The possible extent of these extremes is, not surprisingly, determined by how warm low latitudes are and how cold high latitudes are. Given that we expect that high latitudes will warm much more than low latitudes in a warmer climate, the differenceis expected to diminish, leading to less variance.
31
Nevertheless, we are told by advocates and the media that exactly the opposite is the case, and that, moreover, the modelspredict this (which, to their credit, they do not) and that the basic agreementdiscussed earlier signifies scientific agreement on this matter as well. Clearly more storms and greater extremes are regarded as more alarming than the opposite. Thus, the opposite of our current understanding is invoked in order to promote public concern. The crucial point here is that once the principle of consensus is accepted, agreement on anything is taken to infer agreement on everything advocates wish to claim.
32
At this point, it is doubtful that we are even dealing with a serious problem. If this is correct, then there is no policy addressingthis non-problem that would be cost-effective. Even if we believe the problem to be serious, we have already reached the levels of climate forcing that have been claimed to be serious. However, when it comes to Kyoto, the situation is even worse. Here, there is widespread and even rigorous scientific agreement that complete adherence to the Kyoto Agreement would have no discernible impact on climate regardless of what one believes about climate. Thus, the theme of this meeting is, at least onthis count, appropriate.
33
What about the first possibility: namely that the models on which we are basing our alarm are much too sensitive? Not only is this the possibility that scientists would normally have preferred on the basis of Occam’s famous razor, but it is also a possibility for which there is substantial support.
I will focus on one line of this evidence: tropical warming in the 90's has been associated with much greater outgoing long wave radiation than models produce. This discrepancy points toward the absence of a strong negative feedback in current models.
The discrepancy has been confirmed by at least four independent groups.
34
Chen, J., B.E. Carlson, and A.D. Del Genio, 2002: Evidence for strengthening of the tropical general circulation in the 1990s. Science, 295, 838-841.
Del Genio, A. D., and W. Kovari, 2002: Climatic properties of tropical precipitating convection under varying environmental
conditions. J. Climate, 15, 2597–2615.
Wielicki, B.A., T. Wong, et al, 2002: Evidence for large decadal variability in the tropical mean radiative energy budget. Science, 295, 841-844.
Lin, B., T. Wong, B. Wielicki, and Y. Hu, 2004: Examination of the decadal tropical mean ERBS nonscannerradiation data for the iris hypothesis. J. Climate, 17, 1239-1246.
Cess, R.D. and P.M. Udelhofen, 2003: Climate change during 1985–1999: Cloud interactions determined from satellite measurements. Geophys. Res. Ltrs., 30, No. 1, 1019, doi:10.1029/2002GL016128.
Clement, A.C. and B. Soden(2005) The sensitivity of the tropical-mean radiation budget. J. Clim., 18, 3189-3203.
35
The preceding papers attempted to either attribute the discrepancy to circulation changes or to ‘unknown’cloud properties –except for the last paper.
Clement and Soden(2005) showed that changes in dynamics could not produce changes averaged over the tropics. They showed this using 4 separate models, but it had been shown theoretically in
Chou, M.-D. and R.S. Lindzen (2004) Comments on "Examination of the Decadal Tropical Mean ERBS NonscannerRadiation Data for the Iris Hypothesis". J. Clim.18, 2123-2127.
Clement and Sodenalso showed that the discrepancy could be resolved by allowing convective precipitation efficiency to increase with surface temperature.
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Such a dependence is at the heart of the iris effect which was first found by
R.S. Lindzen, M.-D. Chou, and A.Y. Hou(2001) Does the Earth have an adaptive infrared iris? Bull. Amer. Met. Soc.82, 417-432.
and was theoretically predicted by
Sun, D-Z. and R.S. Lindzen (1993) Distribution of tropical troposphericwater vapor. J. Atmos. Sci., 50, 1643-1660.
In LCH, we attempted to do examine how tropical clouds responded to changing surface temperature, and found that existing satellite data was only marginally capable of dealing with this issue. The results, however, suggested that there were strong negative feedbacks --counter to what models suggest. It was moreover, easy to show that models in no way replicated the cloud behavior that was observed.
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Ground based radar allows the almost continuous measurement of precipitation and the separation of convective precipitation from stratiformprecipitation. In the tropics, both types of precipitation originate in condensation within cumulus towers. However, condensation that does not form precipitation is carried aloft as ice which is detrained to form cirrus from which the condensate eventually falls as stratiformprecipitation.
Precipitation efficiency is given by the relation
It now turns out that the rigorous measurement of precipitation can be done with ground based radar.convective precipitationconvective precipitation + stratiform precipitatione=
38 Using data from Kwajalein Atoll in the western Pacific, we were able to study how evaries with sea surface temperature.
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In addition, the Kwajalein radar allows one to explicitly look at the area of stratiformrain per unit of convective mass flux.
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We see that eincreases about 7.1% per degree C increase in SST (compared with 7.5% estimated by Sun and Lindzen, 1993), and that this increase is associated with a decrease in normalized stratiformarea of about 25% per degree C (which is a bit larger than what was estimated from space observations by Lindzen, Chou and Hou, 2001).
This basically confirms the iris effect, and the fact that models have greatly exaggerated climate sensitivity because, in contrast to models, nature, itself, acts to limit rather than exaggerate the influence of added greenhouse gases.
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The primary implication is that for over 25 years, we have based not only our worst case scenarios but even our best case scenarios on model exaggeration.
As far as I can tell, the main question we ought to be confronting is how long the momentum generated by this issue will prevent us from seeing that it has been an illusion based on model error.
What is the implication of these simple results?
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In the mean time, we can continue to play our parts in the modern version of "The Emperor’s New Clothes."Our descendents will be amused for generations to come.
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