Greenhouse gas emissions push droughts to staggering proportions in southwestern U.S. and northern Mexico
As the southwestern United States and northern Mexico approach their 20th year of worsening drought conditions, scientists fear these regions are headed toward a massive mega-drought the likes of which have been seen only four times in the last 1200 years.
A recent study in Science compares current soil-moisture values with those of the previous four mega-droughts, finding that the current conditions are already even drier than the first three, making this the second-worst drought since 800 A.D. Global warming seems to have played a role, the study suggests. Using climate modeling, lead author Park Williams and his team found that although the affected areas were already headed toward a moderate drought this century, it was greenhouse gas emissions and the related rise in global temperatures that propelled the drought to mega proportions.