Uncertainties

The rapid climate change we are currently experiencing is based on a large-scale physical phenomenon that is relatively easy to understand: the amplification of the greenhouse effect. However, this phenomenon has a wide variety of consequences for the climate, beyond simply raising the air temperature. These consequences are characterized by variable parameters: the “what?” “ (nature of the impact), ”when?“ (timing), ”where?“ (location), ”how?“ (severity), ”how often?" (frequency), etc. For some impacts of climate change, the answers to these questions are marked by considerable uncertainty. Take, for example, changes in precipitation patterns: among the 17 climate simulations on which the TRACC (Reference Warming Trajectory for Climate Change Adaptation) is based, some predict a decrease in annual rainfall in France, while others conclude that there will be an increase. At a more detailed level, the spatial and seasonal distribution of these precipitation patterns is marked by even greater uncertainty. As for the occurrence and severity of isolated rainfall events, forecasting is even more difficult.

We are not all equal in the face of uncertainty. We are not exposed to it in the same way depending on our spatial and social position, and we do not experience it with the same level of stress. Nevertheless, we all share a rather feverish relationship with it and are relatively intolerant of it: our reactions to incorrect weather forecasts for the next day are a good example of this. In the face of a disrupted climate, a disruption that depends on the evolution of greenhouse gas emissions, which is itself uncertain in the medium to long term, adaptation to climate change must also be an adaptation to uncertainty. Often confined in France to flood-prone areas, risk awareness must be spread in order to better understand and respond to sudden climate events. This awareness must enable decision-makers to better adapt the territory they administer and enable populations to better prepare for and respond to such events.