Richard Lindzen fait notamment écho dans cette riche tribune de la pétition anti pensée libre dirigée contre Claude Allègre et Vincent Courtillot, pétition qui fait honte à la France des lumières.

- Olivier

Climate Science In Denial  - Global warming alarmists have been discredited, but you wouldn't know it from the rhetoric this Earth Day. In mid-November of 2009 there appeared a file on the Internet containing thousands of emails and other documents from the Climatic Research Unit at the University of East Anglia in Great Britain. How this file got into the public domain is still uncertain, but the emails, whose authenticity is no longer in question, provided a view into the world of climate research that was revealing and even startling. 

This reassertion, however, continues to be suffused by illogic, nastiness and outright dishonesty. There were, of course, the inevitable investigations of individuals like Penn State University's Michael Mann (who manipulated data to create the famous "hockey stick" climate graph) and Phil Jones (director of the CRU). The investigations were brief, thoroughly lacking in depth, and conducted, for the most part, by individuals already publicly committed to the popular view of climate alarm. The results were whitewashes that are quite incredible given the actual data. 

 In addition, numerous professional societies, including the American Society of Agronomy, the American Society of Plant Biologists and the Natural Science Collections Alliance, most of which have no expertise whatever in climate, endorse essentially the following opinion: That the climate is warming, the warming is due to man's emissions of carbon dioxide, and continued emissions will lead to catastrophe.

We may reasonably wonder why they feel compelled to endorse this view. The IPCC's position in its Summary for Policymakers from their Fourth Assessment (2007) is weaker, and simply points out that most warming of the past 50 years or so is due to man's emissions. It is sometimes claimed that the IPCC is 90% confident of this claim, but there is no known statistical basis for this claim—it's purely subjective. The IPCC also claims that observations of globally averaged temperature anomaly are also consistent with computer model predictions of warming.

There are, however, some things left unmentioned about the IPCC claims. For example, the observations are consistent with models only if emissions include arbitrary amounts of reflecting aerosols particles (arising, for example, from industrial sulfates) which are used to cancel much of the warming predicted by the models. The observations themselves, without such adjustments, are consistent with there being sufficiently little warming as to not constitute a problem worth worrying very much about.

In addition, the IPCC assumed that computer models accurately included any alternative sources of warming—most notably, the natural, unforced variability associated with phenomena like El Nino, the Pacific Decadal Oscillation, etc. Yet the relative absence of statistically significant warming for over a decade shows clearly that this assumption was wrong. Of course, none of this matters any longer to those replacing reason with assertions of authority.

Consider a letter of April 9 to the Financial Times by the presidents of the U.S. National Academy of Science and the Royal Society (Ralph Cicerone and Martin Rees, respectively). It acknowledges that climategate has contributed to a reduced concern among the public, as has unusually cold weather. But Messrs. Cicerone and Rees insist that nothing has happened to alter the rather extreme statement that climate is changing and it is due to human action. They then throw in a very peculiar statement (referring to warming), almost in passing: "Uncertainties in the future rate of this rise, stemming largely from the 'feedback' effects on water vapour and clouds, are topics of current research."

Who would guess, from this statement, that the feedback effects are the crucial question? Without these positive feedbacks assumed by computer modelers, there would be no significant problem, and the various catastrophes that depend on numerous factors would no longer be related to anthropogenic global warming.

That is to say, the issue relevant to policy is far from settled. Nonetheless, the letter concludes: "Our academies will provide the scientific backdrop for the political and business leaders who must create effective policies to steer the world toward a low-carbon economy." In other words, the answer is settled even if the science is not.

In France, several distinguished scientists have recently published books criticizing the alarmist focus on carbon emissions. The gist of all the books was the scientific standards for establishing the alarmist concern were low, and the language, in some instances, was intemperate. In response, a letter signed by 489 French climate scientists was addressed to "the highest French scientific bodies: the Ministry of Research, National Center for Scientific Research, and Academy of Sciences" appealing to them to defend climate science against the attacks. There appeared to be no recognition that calling on the funding agencies to take sides in a scientific argument is hardly conducive to free exchange.

The controversy was, and continues to be, covered extensively by the French press. In many respects, the French situation is better than in the U.S., insofar as the "highest scientific bodies" have not officially taken public stances—yet. 

Despite all this, it does appear that the public at large is becoming increasingly aware that something other than science is going on with regard to climate change, and that the proposed policies are likely to cause severe problems for the world economy. Climategate may thus have had an effect after all.

But it is unwise to assume that those who have carved out agendas to exploit the issue will simply let go without a battle. One can only hope that the climate alarmists will lose so that we can go back to dealing with real science and real environmental problems such as assuring clean air and water. The latter should be an appropriate goal for Earth Day.

Mr. Lindzen is professor of meteorology at the Massachusetts Institute of Technology.

Publié sur :

http://online.wsj.com/article/SB10001424052748704448304575196802317362416.html?mod=rss_Today's_Most_Popular 

***********************************************************************************************************************************

Climate change is simply natural and disaster isn't imminent

By Richard S. Lindzen

last updated: April 04, 2010 01:07:15 AM

To a significant extent, the issue of climate change revolves around the elevation of the commonplace to an ominous omen. In a world where climate change has been the norm, it's now taken as punishment for sinful levels of consumption. In a world where we experience temperature changes of tens of degrees in a single day, we treat changes of a few tenths of a degree in some statistical residue, known as the globally averaged temperature anomaly or GATA, as portents of disaster.

Earth has had ice ages and warmer periods. Ice ages have occurred in a 100,000-year cycle for the past 700,000 years, and there have been previous interglacial periods that appear to have been warmer than the present, despite lower carbon-dioxide levels. More recently, we have had the medieval warm period and the little ice age.

For small changes in the GATA, there is no need for any external cause. The earth never is exactly in equilibrium. The motions of the massive oceans, where heat is moved between deep layers and the surface, provide variability. Examples include El Niño, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation, etc. Recent work suggests that this variability is enough to account for all change in the GATA since the 19th century. To be sure, man's emissions of carbon dioxide must have some impact. The important question, however, is how much.

A generally accepted answer is that a doubling of carbon dioxide in the atmosphere (it turns out that one gets the same value for a doubling regardless of what value one starts from) would perturb Earth's energy balance about 2 percent and this would produce about 2 degrees Fahrenheit warming in the absence of feedbacks. The observed warming over the past century, even if it were all because of increases in carbon dioxide, would not imply any greater warming.

However, climate models predict that a doubling of carbon dioxide might produce more warming: 3.6 degrees to 9 degrees Fahrenheit or more. They do so because within these models the far more important radiative substances, water vapor and clouds, act to greatly amplify whatever an increase in carbon dioxide might do. This is known as positive feedback. Thus, if adding carbon dioxide reduces Earth's ability to cool itself by emitting thermal radiation to space, the positive feedbacks will further reduce this ability.

It is acknowledged that such processes are poorly handled in current models, and there is substantial evidence the feedbacks may be negative rather than positive. For example: 2.5 billion years ago, the sun's brightness was 20 percent to 30 percent less than it is today, yet the oceans were unfrozen and the temperatures appear to have been similar to today's.

This was referred to by Carl Sagan as the "early faint sun paradox." For 30 years, there has been an unsuccessful search for a greenhouse gas resolution of the paradox, but it turns out a modest negative feedback from clouds is entirely adequate. With the positive feedback in current models, the resolution would be essentially impossible.

Interestingly, according to the United Nations' Intergovernmental Panel on Climate Change, the greenhouse forcing from manmade gases is already about 86 percent of what one expects from a doubling of carbon dioxide (with about half coming from methane, nitrous oxide, freons and ozone). Thus, these models should show much more warming than has been observed. But they have arbitrarily removed the difference and attributed this to essentially unknown aerosols.

The IPCC's claim that most of the warming since the 1950s is because of man as- sumed that cur- rent models adequately accounted for natural internal variability. The failure of these models to anticipate that there has been no statistically significant warming for the past 14 years or so contradicts this assumption.

However, the modelers chose not to stress this. Rather, they suggested that the models could be further corrected, and that warming would resume by 2009, 2013, or even 2030. Global warming enthusiasts have responded to the recent absence of warming by arguing that the past decade has been the warmest on record. We are still speaking of tenths of a degree, and the records have come into question. But since we are, according to these records, in a relatively warm period, it is not surprising the past decade was the warmest on record.

Given that the evidence suggests that anthropogenic warming has been greatly exaggerated, so is the basis for alarm. But this basis would 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., all depend not on GATA, but on a regional variables including temperature, humidity, cloud cover, precipitation, direction and magnitude of wind, and the state of the ocean.

This is not to say disasters will not occur as they always have. Fighting global warming with symbolic gestures certainly will not change this. However, history tells us that greater wealth and development can profoundly increase our resilience. One may ask why there has been the astounding upsurge in alarmism in the past four years. When an issue such as global warming is around for more than 20 years, agendas are developed to exploit it. The interests of the environmental movement in acquiring power, influence and donations are reasonably clear.

So, too, are the interests of bureaucrats who seek control of carbon dioxide. After all, carbon dioxide is a product of breathing itself. Politicians see the possibility of taxation that will be happily accepted to save the earth. Nations see exploiting the issue to gain competitive advantages. So do private firms.

Take the case of Texas energy firm Enron. Before disintegrating from unscrupulous manipulation, Enron was one of the most intense lobbyists for the Kyoto Protocol. 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 trillions of dollars, and the commissions will run into many billions.

It is probably no accident Al Gore is associated with such activities. The sale of indulgences is 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.

Finally, there are well-meaning individuals who believe that in accepting the alarmist view of climate change, they are displaying intelligence and virtue. For them, psychic welfare is at stake.

Clearly, the possibility that warming may have ceased could provoke a sense of urgency. For those committed to the more venal agendas, the need to act soon, before the public appreciates the situation, is real. However, the need to resist hysteria courageously is equally clear. Wasting resources on symbolically fighting ever-present climate change is no substitute for prudence.

Lindzen is the Alfred P. Sloan professor of atmospheric science at the Massachusetts Institute of Technology.

Publié sur :