The effects of 1.5 and 2 degrees of global warming on Africa in the CORDEX ensemble
25 May 2018 - 14:45
Nikulin, G., Lennard, C., Dosio, A., Kjellström, E., Chen, Y., Hänsler, A., Kupiainen, M., Laprise, R., Mariotti, L., Maule, C. F., van Meijgaard, E., Panitz, H., Scinocca, J. F., Somot, S. • 2018
There is a general lack of information about the potential effects of 1.5, 2 or more degrees of global warming on the regional climates within Africa, and most studies that address this use data from coarse resolution global models. Using a large ensemble of CORDEX Africa simulations, we present a pan-African overview of the effects of 1.5 and 2°C global warming levels (GWLs) on the African climate. The CORDEX simulations, consistent with their driving global models, show a robust regional warming exceeding the mean global one over most of Africa. The highest increase in annual mean temperature is found over the subtropics and the smallest one over many coastal regions. Projected changes in annual mean precipitation have a tendency to wetter conditions in some parts of Africa (e.g. central/eastern Sahel and eastern Africa) at both GWLs, but models’ agreement on the sign of change is low. In contrast to mean precipitation there is a consistent increase in daily precipitation intensity of wet days over a large fraction of tropical Africa emerging already at 1.5°C GWL and strengthening at 2°C. A consistent difference between 2°C and 1.5°C warmings is also found for projected changes in annual mean temperature and daily precipitation intensity. Our study indicates that a 0.5°C further warming (from 1.5°C to 2°C) can indeed produce a robust change in some aspects of the African climate and its extremes.