Global heating making extreme rain and catastrophic flooding more likely

A warming world is transforming some major snowfalls over mountains into extreme rain, worsening both dangerous flooding like the type that devastated Pakistan last year as well as long-term water shortages, a new study has found.

Using rain and snow measurements since 1950 and computer simulations for future climate, scientists calculated that for every degree Fahrenheit the world warms, extreme rainfall at higher elevation increases by 8.3% (15% for every degree Celsius), according to a study in Wednesday’s journal Nature.

Heavy rain in mountains causes a lot more problems than big snow, including flooding, landslides and erosion, scientists said. And the rain is not conveniently stored away like snowpack that can recharge reservoirs in spring and summer.

“It is not just a far-off problem that is projected to occur in the future, but the data is actually telling us that it’s already happening and we see that in the data over the past few decades,” said lead author Mohammed Ombadi, a Lawrence Berkeley National Laboratory hydrologist and climate scientist.

As the world has…