Global Mean Temperature

The near-surface air temperature (2m temperature) is one of the most important climate parameters. Due to the greenhouse effect, increasing concentrations of heat-trapping gases in the atmosphere generate additional radiative forcing on Earth. This change in radiation balance manifests itself in an increased near-surface air temperature

2m Temperature

The projected changes in 2m temperature show strong regional differences. All scenarios show a marked contrast between warming over the oceans and over land surfaces; warming on land is faster and stronger because the deep ocean can take up large amounts of heat and therefore has a damping effect. The largest temperature changes, however, occur in areas with changing sea ice cover or with changing snow cover on land.


With rising temperatures, the water cycle intensifies and global mean precipitation increases by a couple of percent, depending on the selected scenario. At the same time, however, there is also a redistribution of precipitation, causing some areas to receive more precipitation and others to receive less; the strength of this redistribution varies with the seasons.