Hurricanes in a Warming Climate

There are fundamental differences between the climate of the Southern and Northern Hemispheres. Largely, these differences are dictated by the obvious differences in the geography of the two hemispheres: the Northern Hemisphere is about 50% land, whereas about 90% of the Southern Hemisphere is ocean. This asymmetry gives a much larger seasonal cycle in the Northern Hemisphere (NH) and reduces the response of Southern Hemisphere (SH) climate to imposed perturbations. This is most clearly seen in predictions of future SH climate, where predicted temperature increases caused by anthropogenic warming are considerably muted compared to changes at similar latitudes in the NH (e.g., Knutti and Sedláček 2013). Since the climate effects of anthropogenic carbon dioxide are well-mixed throughout the global atmosphere, the smaller future surface warming in the SH suggests that the future climate response to a combined forcing of surface temperature change and CO2 increases will be different in the SH compared to the NH.