According to a new study, global warming will cause more frequent and intense rainstorms around the world, resulting in heavy economic losses, including the mass destruction of crops, bridges and roads.  The finding is based on an analysis of climate phenomena in the tropics. VOA's Jessica Berman reports.

An Indian commuter makes his way along a waterlogged street after a heavy downpour in Amritsar, 05 Apr 2008

Climate models have long predicted that global warming will lead to an increase in the number and intensity of rainstorms around the world.

A new study provides the first observed evidence of that link.

Experts are concerned that as temperatures rise, more moisture will rise into the atmosphere as a result of condensation, leading to more rain events and devastating floods that destroy agriculture and infrastructure.

"The impact of heavy rain events do [does] have a substantial impact on society," said Brian Soden, a professor at the University of Miami's Rosenstiel School of Marine and Atmospheric Science in Florida. "So what we were trying to do in this study is to actually test the validity of those events by looking at natural variability."

To understand how global warming would drive an increase in the intensity of rainstorms, researchers used the natural climate phenomenon El Nino in the Eastern Tropical Pacific as a laboratory.  

Analyzing 20 years of satellite data, the researchers found a distinct link between rainfall intensity and temperature.  

Rainfall was heaviest when temperatures were warmest during El Nino.  The rains were lightest during the climate phenomenon's cool phase known as La Nina.

"And the other thing we also found that's important is that when we compared these changes to what climate models predicted in response to these warm and cold cycles, that the observed changes in precipitation intensity were actually larger than what the models predicted," he said. "And this suggested that perhaps over the next century the models may actually be underestimating the response of these heavy rain events to global warming."

The study on rainfall intensity and global warming is published this week in the journal Science.