The media immediately took the Climategate

It is the other threat to the après-Copenhague. Much more deaf than the sum of economic interests that led to the long-awaited climate change summit failure. But still this against the background of a round of negotiations which is just beginning. Three weeks before the international summit in the Danish capital, climate-sceptics, those who doubt the validity of the balance established in 2007 by the Group of experts, intergovernmental on the evolution of the climate is suddenly invited in the debate. The controversy caused by a supposed scientific results manipulation orchestrated by researchers of the Climate Research Unit (CRU) of the British University of East Anglia, inspiring the work of the IPCC, propelled on the public stage a debate long confined to the restricted world of laboratories. The media immediately took the "Climategate". Since then, the matter is that fester. To the extent that this week a representative of the Obama administration has seen fit to go to the niche for calm. In charge of climate issues in Washington, Todd Stern downplayed the controversy on the errors of the IPCC, accusing him of "special interests" of wanting to take advantage of the controversy. "Should not only be individual errors and typos or anything anyone could be used to undermine the fundamental consensus that exists among scientists around the world, according to which there is a serious problem, and that is rising," he insisted.

What interests talking about this us responsible And which are just scientists who are challenging the official position of the IPCC Are of simple "deniers" - one of the particularly poorly chosen words which it has given them - in the pay of the large industrial lobbies American Hear one of them, the famous physicist Freeman Dyson, Member of prestigious Institute of Advanced Studies at Princeton University, the subject is much less caricature. "Climate models are powerless to describe the world in which we live." "The real world is muddy, messy and driven by factors that we do not yet understand," he wrote. Like most human activity from carbon contributes to warming of the planet. But how and with what impact, he says that no one could say.

"The climate is an extremely complex system." "Our ignorance on the subject is abyssal and scientists, and politicians, must have the humility to recognize", believes his side John Christy, Professor of atmospheric at the University of Alabama and Director of the Earth System Science Center. Collaborator to the third report of the IPCC, published in 2001, he regretted that "the media and politicians have contributed to polarize the debate between two camps between which the debate is impossible:"anti-carbone"and the"skeptical".

Data deficient

In fact, dissidents of the consensus formed around the IPCC often reflect the isolation in which they face, including as censorship of their contributions and articles. "Any scientist should be skeptical, so we do advance the science." "But I was struck recently discovered following my article on the"Climategate", that much younger colleagues did not dared express their concerns on the climate for fear of harming their career", says Judith Curry, President of the school of atmospheric sciences and the land of the Georgia Institute of Technology. It is one of the few proponents of the theories of the IPCC to cultivate public dialogue with the skeptics. According to her, they pose a key question: "is that the models we say on climate change." "The reality is that uncertainty is enormous," she says.

In the heart of the problem lies the lack of data. The first weather stations appeared in 1849. But these data were not collected or archived with scientific rigor is necessary, to the extent the climate science has not emerged before the 1970s. Still, it took until 1979 that the satellite analyses provide a reliable source of information. Climatologists then embarked on a frantic new scientific field exploration, without always applying with enough consistency test reproducibility to confirm any new discovery. "Nobody had the time nor the motivation to properly archive data because it was important above all to explore." In addition, it was more likely to promote his career in advancing research that by checking the work already done by his colleagues, says Judith Curry. Way, scientific integrity has been neglected and many of my colleagues are now on the defensive as they fear to see their work questioned.

With the lack of the necessary elements to establish the extent of current warming, climatologists have indirect information, or "proxies", used to reconstruct the history of climate (Paleoclimatology). Analysis of tree rings of trees, drilling ice cores are the most used methods. However the climate reconstruction of the last thousand years developed the 1990s under the authority of American climatologist Michael e. Mann is particularly controversial. It was achieved by analysis of rings of Saint Lucia and Balfour pine fir, willingly tightrope trees that grow in the American Southwest. The curve thus obtained, called the "stock of hockey" due to its shape, which shows a pronounced increase in temperatures since the beginning of the industrial revolution, is a central tenet of the report published in 2001 by the IPCC.

"During the debate on the ratification of the Protocol of Kyoto by the Canada, end of 2002, I was interested in what we knew about the history of the temperatures of the last two thousand years, says Steve McIntyre, a Canadian who founded the"skeptical"reference ClimateAudit blog." I asked Michael Mann to give me access to its data; He replied that he did not remember where they were. When his assistant told me that he would have a little time to unite them, I understood that his work was not subject to a rigorous and independent audit. "The the most vexing question on the"hockey stick", revealed to the public by the"Climategate"but known for a long time in the scientific community, concerning the decision taken by Phil Jones, famous climatologist of the CRU and brother of Michael Mann in the IPCC, replace"proxies"rings of trees for the period after 1961 by temperatures recorded directly on the ground. Indeed, the climatologists were seen to "proxies" indicated a decline in temperatures over this period, while modern instruments showed a warming.

Too many misunderstood factors

The authors of the report of the IPCC in 2001 decided not to make mention of this "retail" to not obfuscate their conclusion: the 20th century is the warmest century in the Millennium and the 1990s are the warmest decade of the century. For their part, the skeptics concluded that it was reasonable to completely question the reliability of the analyses of growth rings of trees as the basis for a reconstruction of the history of the climate. Flying at the same time challenging the demonstration of Michael e. Mann and the position of the IPCC.

Their criticisms have been validated in 2006 by two surveys of the National Academy of Science and a trio of statisticians, mandated by Congress. The first considered that the weaknesses of the method did not have a major impact on the results on the last four centuries, but that the findings were less convincing that it went back in time. At the same time, the statistician Edward Wegman found in his testimony to Congress, that the work of Michael Mann were "obscure and incomplete."

Simultaneously, the skeptics consider the climate models with caution. "They exaggerate the current realities and scenarios for the future," said John Christy. He pointed out that too many factors remain insufficiently understood to write the future with certainty. For example, the impact of clouds just beginning to be studied seriously. Decadal climatic oscillations of oceans and solar activity cycles are still ignored by climate models. "It is urgent that governments invest to accelerate research, insists John Christy.". It is dangerous to establish long-term policy when it is still unknown so much.