Climate models reveal how human activity may be locking the American Southwest into permanent drought

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

A new wave of climate research is sounding a stark warning: Human activity may be driving drought more intensely — and more directly — than previously understood.

The southwestern United States has been in a historic megadrought for much of the past two decades, with its reservoirs including lakes Mead and Powell dipping to record lows and legal disputes erupting over rights to use water from the Colorado River.

This drought has been linked to the Pacific Decadal Oscillation, a climate pattern that swings between wet and dry phases every few decades. Since a phase change in the early 2000s, the region has endured a dry spell of epic proportio