The UN’s Autumn Climate Change Conferences coincide with the release of position papers intended to capture the imagination. “The weather of the future looks dire, devastating, deadly and apocalyptic. On the eve of these conferences, which are constantly described as the last chance, the reports announcing bad news are coming back in droves.
Posted yesterday at 11:00 a.m.
The level of alert has not changed with COP27 taking place in Egypt these days. But, some new elements concerning the setting in context deserve to be underlined.
Before COP27: unrealistic warming strategies
Until recently, the Intergovernmental Panel on Climate Change (IPCC) presented all the climate simulations without giving any probability of occurrence. While this approach is laudable for scientists tasked with improving their models, it is of no use to policy makers who need to take action and determine the most appropriate investments for climate adaptation.
The all-out presentation of climate scenarios has opened the door to exaggeration. For a long time the strategy has been to present the worst case scenario. The news provided us with a host of hypotheses ranging from the apocalypse (temperature increases of +5°C to +7°C in 2100) to more comfortable situations that would remain between +1.5°C and +2°C. A size difference.
The catch is that none of these extreme scenarios are likely based on known data. On the one hand, the exaggeration by the top does not hold water for a first reason: a simple calculation of the exploitable reserves of oil and natural gas allows us to eliminate this kind of hypothesis. These worst-case scenarios are also based on coal consumption tripling by the end of the century. Can we believe it? We simply don’t have enough carbon to burn to wait for such temperature increases.
These pessimistic scenarios also have in common a very strong population growth, where water stress is greatest and where the climate impact will be greatest. Flagrant contradiction.
The strategy has suddenly changed in favor of exaggeration from below since the Paris conference in 2015. The climate crisis seemed managed in enchantment, as if it was enough to pull out a magic wand to remake the world, it is that is to say, in defiance and in spite of the reality and the titanic efforts to complete the technological and social revolution which is essential. The powerful of the Western world have invented a game: outbid, amplify the last objective, shorten the horizon of action, but without wanting to be accountable.
The entropic heritage of the oil civilization is gigantic. This is the main reason that leads us to conclude that the objective of +2°C is improbable, and even more so than that of +1.5°C. They were realistic when they were mentioned in the last century. But the job was not done. Decades later, time is running out.
COP27: more realistic warming scenarios
IPCC or UN publications do not yet speak of “most likely scenarios”. Rather, we present reference scenarios such as: “If current climate control policies are not improved”, we are heading towards temperature increases that would be in the range of +2.4°C to +2.7 °C, roughly. It corresponds exactly to my calculations which are largely probabilistic. Moreover, the news is putting more and more doubts about the +1.5°C and +2°C targets which are forcing us to change the world within seven years! The invasion of Ukraine also changed a perception, the importance of nuclear power and natural gas.
Rigor finally takes over.
The watchword remains the same: we must get to work now, because limiting the rise in temperature to around 2.5°C is no small task.