Global warming could cause a “mega drought” in the southwest. A place where water supplies are already over taxed. A study published in the journal Science lays out a grim picture.

Researchers studied 19 computer models of the climate, using data dating back to 1860 and projecting into the future, to the year 2100. The same models were used in preparing the reports of the Intergovernmental Panel on Climate Change.

The consensus of the models was that climate in the southwestern United States and parts of northern Mexico began a transition to drier conditions late in the 20th century and is continuing the trend in this century, as climate change alters the movement of storms and moisture in the atmosphere. The models show the drying trend continuing all the way to 2100 — for more than 90 years.

“If these models are correct, the levels of aridity of the recent multiyear drought, or the Dust Bowl and 1950s droughts, will, within the coming years to decades, become the new climatology of the American Southwest,” the researchers wrote.(via)

Currently most of the water used in the southwest goes to farming. With an ever growing number of people moving to the “sun belt” that water will be spread out more and more. In a nutshell unless we invent stillsuits, we are going to have to move a lot of people out of the region. We simply can not have that many people living in the desert.