Weather extremes could become more common as the climate warms this century, because extreme cooling events in the Pacific Ocean are predicted to occur more often.

La Niña events occur when the equatorial Pacific cools, causing droughts and floods worldwide. Wenju Cai of the Commonwealth Scientific and Industrial Research Organization in Aspendale, Australia, and his colleagues analysed the occurrence of significant La Niñas and related El Niño events from 1900 to 2099, simulated under rising concentrations of greenhouse gases in the atmosphere. The researchers found that the number of extreme La Niña events increased from one every 23 years to one every 13 years in the twenty-first century.

Most of the severe La Niñas will follow severe El Niños, resulting in wide, annual swings between opposite extreme weather events, the authors suggest.

Nature Clim. Change http://doi.org/zph (2015)