Global climate change will lead to heavier summer downpours and more frequent flash floods, according to a new report.
Researchers from the Met Office and Newcastle University have produced a study, published in the journal Nature Climate Change, where they found that there could be five times the number of “extreme rainfall events” exceeding 28mm per hour, under extreme warming projections.
Dr Lizzie Kendon, lead author of the research at the Met Office, said:
“Until now, climate models haven’t been able to simulate how extreme hourly rainfall might change in future. The very high resolution model used in this study allows us to examine these changes for the first time.
“It shows heavier summer downpours in the future, with almost five times more events exceeding 28mm in one hour in the future than in the current climate – changes we might expect theoretically as the world warms. However, we need to be careful as the result is only based on one model – so we need to wait for other centres to run similarly detailed simulations to see whether their results support these findings.”
The scientists improved the resolution of the model by using 1.5km grid spacings instead of the normal 12km over southern England, and it took the Met Office supercomputer nearly nine months to make the calculations.
Prof Hayley Fowler, from Newcastle University’s School of Civil Engineering and Geosciences, and lead on project, added:
“We need to understand about possible changes to summer and winter rainfall so we can make informed decisions about how to manage these very different flooding risks in the future. The changes we have found are consistent with increases we would expect in extreme rainfall with increasing temperatures and will mean more flash floods.