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Which measures would you take in Copenhagen?

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Which measures would you take in Copenhagen?

From December 7 to 18, the 15th United Nations climate conference is being held in Copenhagen. At this political summit, government experts from around the world will try to reach agreements on the necessary measures for limiting climate change. Discussions will be based on the conclusions of the intergovernmental panel on climate change (IPCCNouvelle fenêtre). The Pierre Simon Laplace Institute (IPSLNouvelle fenêtre) is an important component of this body. We interviewed its director, Hervé Le Treut.



People are talking of an ultimatum at Copenhagen. Is this correct? 

The term can be misunderstood. We are not really faced with an ultimatum, but with very difficult political negotiations. It is by no means certain that the contradictions between States with different interests will be completely resolved. That is not to say that the situation is not urgent; it really is! If we want to avoid the negative effects of climate change, it is crucial that politicians decide on common actions that will have a real effect throughout the next decades.


One of the issues at stake in Copenhagen is to define the successor to the Kyoto protocol. Is this protocol obsolete?

The Kyoto protocol was defined in 1997. Since then, things have changed considerably. China is currently emitting as much quantity of greenhouse gas as the United States. Now, the United States did not ratify the Kyoto protocol and China, like all emerging countries, was exempt from taking measures. However, the atmosphere ignores borders, which means we cannot reduce greenhouse gas emissions without their participation. The same goes for India, Brazil and all the other emerging countries. These fast-growing countries must be convinced to act on the climate change that they did not initiate, but that they maintain today and whose effects they are the first to suffer from. Whatever the results of Copenhagen, we are talking about a long term process.


What other issues are at stake at the summit? 

Climate models show that the vulnerability to change varies a lot from one region of the world to another, and that climate change is partly inevitable. Therefore, the second issue at Copenhagen is the creation of a fund to help poor countries manage the effects of climate change. It is a question of international justice, of industrialized countries responsibility.

Developing countries are often the most vulnerable in the face of climate deregulation, though they are not responsible for it. Climate change is felt immediately in the semi-arid zones of the inter-tropical region, where there is often only one rainy season. The decrease in rainfall can have catastrophic consequences for agricultural production. “Climate refugees” – who are really “refugees from poverty” – are already appearing in the Horn of Africa. The climate-poverty pair is the most serious threat of all for these populations.


Is the catastrophe film “The Day After Tomorrow” an accurate representation of what we will be confronted with?

This representation of the future by a brutal glaciation which transforms the world within a few days is, of course, a completely false image of what might happen. Climate change will be much slower. It will take decades. Deltas being swallowed up by the oceans, powerful cyclones hitting more frequently, wells drying up; these effects will come about little by little. We are at the beginning of a process which will progressively establish its grip on countrysides and natural resources. The best metaphor is perhaps that of a knot tied around our planet which is slowly but inexorably getting tighter.


How much time do we have left to backtrack?

If we do nothing, the 2°C level of climate change, considered to be the danger level which must not crossed, will be reached by 2050. But the climate is a huge ship and it cannot be slowed down just like that. Greenhouse gases have a long lifespan in the atmosphere: up to a century for CO2. The oceans take a long time to heat up, but also to cool down. We have little time left. We must act before 2020.


Which measures would you take if instead of being the director of the IPSL, you were the president of France?

The two functions require very different skills… I try to participate in the debate as a scientific expert, and that would be a fairly brutal role change! I think the first issue is to establish strong policies for reducing greenhouse emissions, while bearing in mind that they will only be accepted if they are fair. But in terms of playing a political role, I think it would be just as interesting to be the mayor of a large city or regional president, as it is often on that scale that important measures concerning transport and housing are taken.


Interview by Gaëlle Lahoreau

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