450 of them have been selected as lead authors

Should we abolish or at least reform the "group of intergovernmental experts on the climate change" (IPCC), awarded in 2007 by the Nobel Prize in peace, as the claim "climate skeptics" While the China and the India have their signature to the agreement in Copenhagen, and while countries like the US and the Japan, negotiate internally the binding laws, reviews take place in the United States, Republican Senator James Inhofe, a fierce opponent to the climate of the Obama administration Act, denounced the "kitchen" of the IPCC and advertising of legal proceedings against 20 high-level scientists. American advocates of creationism suggest even to add warming to the theory of evolution, the topics do not teach in the classroom! Taken in reverse, the majority of the scientific community, who think as stated by the IPCC in its latest report that "global warming is unequivocal", just beginning to organize its response. The IPCC has thus to submit to the United Nations the independent Committee to study its methods of work (see page 17), while British, British (Met Office) weather service said, after having reviewed hundreds of recent scientific publications, that "science reveals a consistent picture of a global change that is clearly the footprint of gas emissions produced by human greenhouse". Taking important position since it reflects that started the "climategate", with piracy in November, just before the Conference in Copenhagen, over a thousand e-mails and 3,000 documents dated from 1996 to 2009 on the server of the Centre for research on climate (CRU) of the University of East Anglia. Main victim: Director, climatologist Phil Jones, accused of manipulating the data, and especially to deny access to little convinced scientists. In fact, it was not allowed to communicate, these information belonging to the national weather service, unless explicit agreement of the countries concerned. Since November, the University, which still awaits green light from seven countries, released 80 of the data. Has resigned, Phil Jones, he is subject to a double survey: initiated by one parliamentary Committee of inquiry, the other by the University itself. He admitted sending a few "infects" mails to some skeptics, explaining that the CRU, harassed by requests for information, could no longer cope.

Neutral and objective

But in January, the "climategate" took another dimension. Taken in turn to party for having committed an error in its forecasts on the melting of the glaciers of the Himalayas as early as "2035" instead of 2350, then on the risk of flooding to the Netherlands, the IPCC is now itself contested. In France, former Minister of National Education, Claude Allègre, involves including "the objectivity and quality" of his reports. According to him, "the IPCC should be either purely and simply deleted or deeply reformed." But what is that the IPCC just Open to all UN member countries, it is an intergovernmental body established at the request of the G7 in 1988, under the auspices of the World Meteorological Organization (WMO) and of the Programme of United Nations for the environment (UNEP). With a mission: "assess, without bias and how systematic, clear and objective, scientific, technical and socio-economic information which is necessary to understand the scientific basis of the risks linked to human-induced climate change, identify more precisely the consequences of this change and consider of potential adaptation and mitigation strategies". To fill, the IPCC assesses the State of knowledge at regular intervals: his first report was published in 1990, the following in 1996, 2001 and 2007. Each Edition comprises three books of more than 1,000 pages. The first deals with the physics of the climate, it is he who answers the question of the influence of greenhouse gases. For the last edition, more than 5000 scientific publications were passed in review to climate diagnosis of the planet. The second " book", one where the errors on the Himalayas and the Netherlands, were made exploring the predictable impacts of climate change, while the third is studying the socio-economic impacts of the damage and the measures that can be expected to mitigate climate change. Each must be "policy-relevant, never policy-prescriptive": clearly, they must inform political decision, but in a neutral manner, without Guide.

With a President, Rajendra Pachauri, elected by the Member States, assisted by an Office of about 30, voluntary scientists and a secretariat of less than 10 people the

IPCC, lightweight hosted by WMO, has no research teams and barely a budget. To write his reports, he launches an international call to authors, that relays in each country the "contact point" IPCC. In France, the national Observatory on the effects of climate change in the Ministry of sustainable development currently centralized applications for the drafting of the fifth report, expected in 2014, after having contacted all organizations research, universities, academies, etc. A nominations Committee will verify their expertise on the basis of their publications, before sending to the IPCC, Geneva, a list of experts. "But all those who are not selected will remain registered, and will be mobilized for the critical review of chapters", says the Department. Each chapter is supervised by two coordinators and written by 20 main authors, who undertake jointly and severally on the content, everyone has a right to veto. "It is very heavy, time equivalent to four or five months, and entirely volunteer work," explains Hervé Le Treut, leader of the Institut Pierre-Simon-Laplace, who coordinated a chapter on the history of climate science.

450 lead authors

But candidates are not missing: for the last edition, they were 2,000 from 130 countries. 450 of them have been selected as lead authors. A new candidate for 2014, Hervé Le Treut explains: "this is a collective sharing of knowledge and research time, which allows us to have access to lot of information, and for me, it's interesting to work not only on my own ideas, but on those of others also and try to make a synthesis." Can a climate sceptic be candidate "Of course, for which he has published", underlines. A study questioning the theory of global warming can go unnoticed No, for little it seems in a good journal, slice Jean-Charles Hourcade, Director of research at CNRS.

Hervé Le Treut adds that if the IPCC, unique example of international scientific cooperation, can exist, is carried out for decades by human efforts to predict time to anticipate its crops, its navigation, trade... WMO was created as early as 1873 to harmonize and coordinate the weather "stations", and to develop standardized measures processes... "The scientific community of climate existed prior to the IPCC, is alerted to the dangers of greenhouse gases," said Hervé Le Treut. "The economic importance of the weather forecast is that this discipline has always been abundant credits and never had need of warming for money, as stated in some," said an expert weather France.

The IPCC is therefore far from being a "group of pressure green disguised as scientists", said Jean-Charles Hourcade du CNRS. Remains to know if its working methods do not produce consensus biased, that gum controversy, as claimed by his opponents. A priori, the writing of the reporting process is rigorous. A first version of each chapter is sent to the scientific community to collect its notice and comment, and authors must be justified in writing when they refuse to integrate a counterproposal. Completed and corrected, the second version is again examined before the final drafting. Then comes the more controversial step: the drafting of the "summary for policymakers", whose synthesis must be validated-line in the plenary, in the presence of representatives of all States. Dominique Dron, Jean-Louis Borloo Advisor, thus recalls attending strenuous discussions raised by China, for a simple note at bottom of page. Some denounce that a suspect mixture between science and policy. "It is rather a strong way to give a voice to the dissenting opinions," Note Jean-Charles Hourcade, recalling that, despite the presence of strongly hostile to the theory of global warming countries as Saudi Arabia or George Bush's America, the IPCC confirmed the anthropogenic climate change.

"If it had to invent a robust, non-political process to find a neutral expertise, I don't know what could be inventing other," wondered on the Government. Without this deliberation, only tool, no doubt, extreme views would audible, resulting in an impossible debate as for GMOs. "The IPCC is a middle voice, accused by some to be too moderate by others too alarmist", said Hervé Le Treut. Asking for its removal, climate-sceptics deny the usefulness of the only tool of scientific expertise developed by the international community, involving an unprecedented attempt to global governance of a public good: the atmosphere.

ANNE BAUER