What was done
In a small "scientific correspondence" item, the authors list a number of reports of decreasing pan evaporation in European Russia, Siberia, India, Venezuela, and the eastern and western United States.  They note that these observations have commonly been interpolated to suggest that terrestrial evaporation has been decreasing.  On the basis of simple physical reasoning, however, they demonstrate that just the opposite is more likely to be the case, i.e., that terrestrial evaporation has likely been increasing.

What was learned
The results of the authors' analysis suggest that earth's hydrologic cycle is intensifying over large regions of the globe.

What it means
The authors conclusions are consistent with numerous independent meteorological records that indicate significant increases in precipitation and cloud cover over the past few decades.  These findings suggest that both agricultural crops and natural ecosystems will, on average, be less susceptible to drought if the earth continues to warm, especially when factoring in the increasing water use efficiency that rising levels of atmospheric CO2 confer upon plants.