Climate change will yield more extreme rainfall in the future, shows a new study.
The study was carried out by researchers at MIT (Massachusetts Institute of Technology) and Caltech.
Previous studies have shown that average annual precipitation will increase in both the deep tropics and in temperate zones, but will decrease in the subtropics.
It is the frequency of these extreme events that was the subject of this new research, which was conducted by Paul O'Gorman, assistant professor in the Department of Earth, Atmospheric and Planetary Sciences at MIT, and Tapio Schneider, professor of environmental science and engineering at Caltech.
Model simulations used in the study suggest that precipitation in extreme events will go up by about 6 percent for every one degree Celsius increase in temperature.
Separate projections published earlier this year by MIT's Joint Program on the Science and Policy of Global Change indicate that without rapid and massive policy changes, there is a median probability of global surface warming of 5.2 degrees Celsius by 2100, with a 90 percent probability range of 3.5 to 7.4 degrees.
Specialists in the field called the new report by O'Gorman and Schneider a significant advance.
According to Richard Allan, a senior research fellow at the Environmental Systems Science Center at Reading University in Britain, "O'Gorman's analysis is an important step in understanding the physical basis for future increases in the most intense rainfall projected by climate models."
The basic underlying reason for the projected increase in precipitation is that warmer air can hold more water vapor.
So as the climate heats up, "there will be more vapor in the atmosphere, which will lead to an increase in precipitation extremes," O'Gorman said.