A Theory on Regional Impacts of Global Warming

Abstract Although spatial patterns of the observed and projected global warming are uniform with some relatively small variability, the magnitude and even sign of the projected regional impacts on crop yields, transmission of infectious diseases, outdoor days, and deadly heat waves, among other phenomena, vary significantly between different regions. Here, we offer a theory explaining how an apparently uniform warming with small variability can produce significantly more diverse regional impacts. The natural phenomena behind these impacts are governed by temperature thresholds dictating how the phenomena nonlinearly react to surface temperature, defining optimal ranges. Depending on how the background temperature at any location compares to these thresholds, the nature of the regional impacts of global warming, in sign and magnitude, may vary significantly in space despite relatively uniform warming. Hence, the spatial variability of historical temperature distribution emerges as a significant determinant of some of the projected regional impacts of global warming.