Abstract:

Surface temperature and relative humidity respond more strongly to climate change over continents than over oceans. These land-ocean contrasts are among the most robust features of global warming, yet are only beginning to be understood. Here I develop a quantitative theory for the response of continents to climate change based on principles of atmospheric dynamics and moisture transport. The theory is applied to a hierarchy of climate models and to observational data, and is found to capture both past and projected trends in annual-mean land temperature and humidity. The warming and drying over land in recent decades is shown to be directly linked to neighbouring oceans, rather than to local land-surface processes. Implications for extreme temperatures in a warming climate are also discussed.