For every 1 ºC of global warming, the frequency of the heaviest rainfalls will nearly double.

Very heavy rainfalls that are rare in our current climate are likely to become more common as precipitation patterns shift in a warming world.

Scientists have projected that climate change will increase average global precipitation, because in a warmer atmosphere the air has higher concentrations of water vapour. For the same reason, the heaviest downpours of the future might be even more drenching than the most intense rains of today.

Gunnar Myhre at the Center for International Climate Research in Oslo and his colleagues investigated whether global warming might also change the frequency of extreme precipitation events. Using historical weather records and climate-model simulations, the team found that the heaviest precipitation events of today will probably occur almost twice as often with each further degree of global warming.

The total amount of precipitation from extreme weather events is therefore also likely to roughly double per degree, with potentially severe impacts on societies.