Global Climate Change and Local Severe Weather Phenomena: Is There a Possible Synthesis Among These Apparent Antitheses?

Abstract

A significant percentage of atmospheric threats for people and property are associated to severe weather events, e.g., to phenomena that occur at small scales (say a few kilometres) and in short amounts of time (say from a few minutes up to a few hours). For this reason adaptation policies would achieve relevant benefits from a circumstantial estimate of how frequency and intensity of these severe weather events might change in the future due to the global climate change. Even if state-of-the-art climate models, both global and regional, can supply precise information on how much and how fast global temperature and rain pattern might change due to climate variations, the same numerical models can not take into account directly small scale events. Nevertheless, the challenge of global change impacts on severe weather is not a lost battle, or at least a battle that is not worth to be fight, this because there are a few possible and complementary approaches, both based on climate models, that can be taken into account. Unfortunately, even the previous mentioned approaches would be correct, state-of-the-art climate models might still be not ready for this task because of their troubles in reproducing correctly the large scale quantities (the ingredients) necessary to infer the needed information on the future frequency and intensity of local severe weather events. Climate models, however, already have a lot of room to be improved with parametrizations (the so called “physics” of the models) that might better reproduce a wide variety of atmospheric behaviours. A lot of work has to be done, but the road is not yet closed, and does not seem, so far, that there are insurmountable walls at the horizon.