Nature 509, 479–482 (2014)

Global warming will lead to an increase in atmospheric moisture due to increases in evaporation and the holding capacity of the atmosphere. The Arctic is expected to have one of the highest global increases in precipitation under climate change and enhanced poleward moisture transport is typically reported as the cause.

Richard Bintanja and Frank Selten, of the Royal Netherlands Meteorological Institute, investigate projected Arctic precipitation trends, up to the year 2100, using output from 37 global climate models (which contribute to the Coupled Model Intercomparison Project phase 5, CMIP5). The projected increase in precipitation is found to be caused by retreating winter sea ice, which enhances evaporation and intensifies the Arctic hydrological cycle. Precipitation increases are projected to peak in late autumn and winter. Poleward moisture transport does contribute to precipitation changes (particularly those occurring in late summer and autumn) but to a lesser extent than warming and reduced sea ice.