Scientists: Climate change could cause storms like Harvey

WASHINGTON: By the time the rain stops, Harvey will have dumped about one million gallons of water for every man, woman and child in southeastern Texas – a soggy, record-breaking glimpse of the wet and wild future global warming could bring, scientists say.

While scientists are quick to say climate change didn’t cause Harvey and that they haven’t determined yet whether the storm was made worse by global warming, they do note that warmer air and water means wetter and possibly more intense hurricanes in the future.

“This is the kind of thing we are going to get more of,” said Princeton University climate scientist Michael Oppenheimer. “This storm should serve as a warning.”

There’s a scientifically accepted method for determining if some wild weather event has the finger- prints of man-made climate change, and it involves intricate calculations. Those could take weeks or months to complete, and then even longer to pass peer review.

In general, though, climate scientists agree that future storms will dump much more rain than the same size storms did in the past.

That’s because warmer air holds more water. With every degree Celcius, the atmosphere can hold and then dump an additional 7% of water, several scientists say.

Global warming also means warmer seas, and warm water is what fuels hurricanes.

When Harvey moved towards Texas, water in the Gulf of Mexico was nearly 1°C warmer than normal, said Weather Underground meteorology director Jeff Masters.

Several studies show that the top 1% of the strongest downpours are already happening much more frequently.

Also, calculations done on Monday by MIT meteorology professor Kerry Emanuel show that the drenching received by Rockport, Texas, used to be maybe a once-in1,800-years event for that city, but with warmer air holding more water and changes in storm steering currents since 2010, it is now a once-every-300-years event.