Temperature changes due to global warming have been easier to detect and attribute than global warming changes in precipitation. Additionally, climate model global warming simulations often disagree on particulars of tropical rainfall predictions. J.D. Neelin and colleagues examined results from 11 simulation models of human-caused global warming to find 21st-century predictions for which some level of model agreement can be found.
The simulations agree that there will likely be drying trends along the margins of large-scale convective regions, especially in the Caribbean-Central American region. The models disagree on exactly when the trend is expected to be detected in the Caribbean-Central American region, however; models estimate that the trend already achieved statistical significance as early as 1994 or will achieve it as late as 2054.
Historical data support the drying trend in this region, with estimates of the rainfall decrease ranging from 5 to more than 30% of average rainfall over a century. It is plausible but still uncertain whether this trend is due to human causes, the researchers say.
"Tropical drying trends in global warming models and observations," by J.D. Neelin, M. Münnich, H. Su, J.E. Meyerson, and C. Holloway
MEDIA CONTACT: J.D. Neelin, Department of Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics, University California, Los Angeles;