GFDL - Geophysical Fluid Dynamics Laboratory

This is an animation of a multi-model estimate of the expected value of runoff change (relative to the historical period 1900-1970) under the SRES A1B emissions scenario. The “flickering” of colors back and forth is mainly an artifact of the way the data have been processed–internal variability of the climate system has not entirely been removed. The actual estimate of the signal of changing climate is seen in the gradual shift in colors from light to dark. It should be kept in mind that the future will have both a climate-change signal and internal variability; the latter will be capable of causing large departures from “climatic normal” or expected conditions in any given year.