Trends in tropical rainfall over land could provide a signal of global warming, with very wet and very dry months both projected to become more frequent as temperatures rise.
Benjamin Lintner at Rutgers University in New Brunswick, New Jersey, and his colleagues compared the results from climate models simulating rainfall for 1975–99 and 2075–99. The researchers found that dry areas will tend to become drier by the end of this century as Earth warms, whereas rainfall will increase in wet areas.
The team also compared rainfall simulations with measurements obtained between 1979 and 2008. However, there was no clear link between changes in tropical precipitation and recent temperature increases. This suggests that natural climate variability, in addition to global warming, is important in influencing tropical rainfall trends.
J. Geophys. Res. http://dx.doi.org/10.1029/2012JD017499 (2012)