Une seule journée d’observation des températures et de l’humidité à l’échelle mondiale suffit à mesurer l’impact du changement climatique. Alors que pendant des générations, les climatologues faisaient la distinction entre la météo, que l’on étudie quotidiennement, et le climat, résultat au long cours d’évolutions latentes, une équipe de chercheurs suisses a ainsi mis en évidence que, depuis 2012, chaque jour, sans exception, porte la marque du réchauffement planétaire. Si cette conclusion semble évidente pour ...
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Les projections climatiques indiquent une augmentation de la fréquence et de l’intensité des phénomènes météorologiques extrêmes. Selon l’OIT, la chaleur excessive au travail a des effets de deux ordres : — sur la santé des travailleurs, en particulier ceux amenés à travailler à l’extérieur et qui doivent fournir des efforts physiques significatifs : les risques sont parfois mortels ; — au niveau collectif, elle diminue le nombre d’heures travaillées et la productivité, donc la richesse produite. Ces effets se font davantage ...
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In issue 380 of Futuribles in December 2011, Antonin Pottier analysed in detail the workings of what is today termed “climate scepticism” – namely the propensity of certain individuals to contest the reality of climate change on the basis of pseudo-scientific arguments. He emphasized particularly that what fuels the debate on climate change is, largely, the degree of uncertainty inherent in the consequences to be anticipated from observation of the facts, not the description of the facts itself. In his view, the main aim of climate sceptics is to block the political measures for combating climate change. However, since they do not admit to this political posture, they choose instead to deny the scientific reality.
This month, Futuribles complements this socio-psychological analysis of climate-sceptical discourse with an – in this case, wholly scientific – analysis of what we know (or do not know) about climate change on our planet. Pierre Morel gives a detailed account of the state of our knowledge in the climate field and what we are able to predict in the medium/long-term. After reminding us of the influence of atmospheric meteorological processes on the climate, he specifies the extent of global warming observed since 1850 and the main origin of that warming, as revealed by the current state of knowledge: the increase in the concentration of greenhouse gases. He then describes the changes in meteorological regimes (showing also the limits of climate simulation models), the modifications of hydrological regimes, and also the prospects for rises in sea levels. He also specifies the mechanisms that may potentially amplify all these phenomena and the climate disasters that might ensue. Lastly, he shows what are the scientific data that cannot be disregarded, the consequences of which are now inescapable (melting of the ice-caps, rises in sea level etc.), the only remaining uncertainty in this connection being the date at which these things will happen. “In this perspective,” Morel concludes, “the continuation of our model of civilization comes at the cost of a fundamental revision of the current paradigm of economic and demographic growth.”
Following the violent storms that struck France in December 1999 and their dramatic aftermath, we asked three eminent specialists for their brief reactions to the questions: Was this a one-off, chance phenomenon or a sign of what lies ahead, because of climate change? Were the storms predictable? What precautions could have been taken? What lessons can be learned from these events and their consequences, and the way in which they were handled?
The first of these specialists is André Lebeau, who looks first at the forecasting aspect and then at the question of prevention.
He reminds us that Météo France had put out a storm warning 24 hours earlier. But it is true that the strength of the storm was underestimated, and an important issue is whether progress can be made in improving the accuracy of forecasts sufficiently far ahead. This is a difficult question to answer since it involves the impact of human activities on climate change.
As to the question of prevention, André Lebeau distinguishes three levels: first, the unavoidable damage caused to the physical environment; then, appropriate action by the general public, which is clearly not as aware of the possible risks in metropolitan France as people are in areas that are more often faced with catastrophes of this kind and where they take greater precautions. Finally, says André Lebeau, it is obvious that if such phenomena became more frequent, much stronger precautionary measures would certainly have to be taken.