Overview of Climate Changes and Illustrative Impacts - Climate Stabilization Targets - page 30

and they also project drying in the dry season in the south and southwest
United States and Mexico (see Figure O.1). {4.2}
Streamflow Changes
Widespread changes in streamflow are expected in a warmer world,
with many regions experiencing changes of the order of 5-15% per degree
of warming. Streamflow is a key index of the availability of freshwater, a
quantity that is essential for human and natural systems. Changes in stream-
flow depend upon both evaporation (and hence warming) as well as pre-
cipitation. In regions where decreases in precipitation are predicted, these
decreases usually will be accompanied by larger decreases in streamflow.
FIGURE O.1 Estimated changes in precipitation per degree of global warming in the three driest consecu-
tive months at each grid point from a multi-model analysis using 22 models (relative to 1900-1950 as the
baseline period). White is used where fewer than 16 of 22 models agree on the sign of the change. One
ensemble member from each model is averaged over the dry season and decadally in several indicated
regions including southwestern North America and Alaska, as shown in the inset plots. Adapted from
Solomon et al. (2009), with additional inset panel for Alaska (courtesy R. Knutti) provided using the same
datasets and methods as in that work. {4.2}