Abstract
Idealized general circulation models (GCMs) suggest global-mean
precipitation ceases to increase with warming in hot climates. However,
it is unclear if this occurs in more comprehensive GCMs. Here, we
examine precipitation over a wide range of climates simulated with
comprehensive GCMs. We find that in the Community Atmosphere Model,
global-mean precipitation increases approximately linearly with
global-mean surface temperatures up to about 330~K,
where it peaks at
5~mm~day$^{-1}$. Beyond
330~K, global-mean precipitation decreases substantially
despite increasing surface temperatures. This occurs because of
increased atmospheric shortwave absorption from water vapor, which
limits shortwave radiation available for surface evaporation.
Precipitation decreases in the tropics and subtropics, but continues to
increase in the extratropics due to increased poleward moisture
transport. Precipitable water increases everywhere, resulting in longer
water-vapor residence times and implying more episodic precipitation.
Other GCMs indicate global-mean precipitation might exhibit a smaller
maximum rate and begin to decrease at lower surface temperatures.