Future population transgress climatic risk boundaries of extreme temperature and precipitation

Taichi Sano, Taikan Oki

Anthropogenic climate change is influencing the frequencies of extreme weather events. Considering the adaptability to extreme climatic risks in the future, we focused on determining whether humans have been exposed to the risks before. We define the rim of two-dimensional histograms of population under 20-year extreme temperature and precipitation as a climatic risk boundary. More than 30% (16.3%) of world population in South Asia, sub-Saharan Africa, and other regions will transgress the climatic risk boundary by the end of this century under RCP8.5 (RCP2.6) scenario. While many areas with large cities will remain within the global climatic risk boundary, they will transgress their regional climatic risk boundaries. This study shows that it is also necessary to consider the limits to adaptation for each appropriate area, considering the cultural, technological, and social transferability of adaptation. This study will help refine public perceptions of extreme climatic risks and lead to more efficient policy making.

Environmental Research Communications: