Evolution of Land Surface Air Temperature Trend

The global climate has been experiencing significant warming at an unprecedented pace in the past century1, 2. This warming is spatially and temporally non-uniform, and one needs to understand its evolution in order to better evaluate its potential societal and economic impact. In this paper, the evolution of global land surface temperature trend in the last century is diagnosed using the spatial–temporally multidimensional ensemble empirical mode decomposition method3. We find that the noticeable warming (>0.5 K) started sporadically over the global land and accelerated until around 1980. Both the warming rate and spatial structure have changed little since. The fastest warming in recent decades (>0.4 K/decade) occurred in northern midlatitudes. From a zonal average perspective, noticeable warming (>0.2 K since 1900) first took place in the subtropical and subpolar regions of the Northern Hemisphere, followed by subtropical warming in the Southern Hemisphere. The two bands of warming in the Northern Hemisphere expanded from 1950 to 1985 and merged to cover the entire Northern Hemisphere.