Do "Megadroughts" Spell Doom for the West?

Do "Megadroughts" Spell Doom for the West?

Can you imagine if the current drought in Texoma lasted forty years?

That's exactly what a new NASA study says might be the case for the western part of the United States.

Climate scientists used tree rings to look into the distant past and compared them with climate models to forecast into into the future.

"What our results show is in the future we can expect droughts to last 20, 30, or 40 years," NASA Climate Scientist Ben Cook said.

Currently, with 400 parts per million of carbon dioxide in the atmosphere, the likelihood of a drought lasting more than 30 years is 12%. If greenhouse gases stopped increasing in the future, scientists found that probability still skyrocketed to more than 60%. And if emissions continued to increase, the western United States has an 80% possibility of a megadrought.

"These droughts are likely to have major implications and major stresses on water resource use in the United States because their longer droughts than anyone has experienced," Cook explained.

Megadroughts have happened before in North America- between 1100-1300 A.D (referred to as the Medieval Climate Anomaly), but when those megadroughts were compared with predictions for the 21st century, the dry periods would be more severe this time around.

"We expect that these droughts are going to begin in the middle of the 21st century, and they are going to present a very large management challenge to agriculture, the ecosystem, and people," Cook said.

In the southwest, climate change could cause reduced rainfall and warmer temperatures, leading to more water evaporating from the soil- water that we desperately need.

These "dooming" projections are partially based on climate models, so they are certainly not set in stone. Cook said that at the end of the day, computer models are the only tool scientists have to investigate future changes in our climate.

Dave Caulfield, Newschannel 6