A "megadrought" that grips the Southwest has broken another record, according to a new study. The last 22 years now rank as the driest such period since at least 800 AD, with human emissions of greenhouse gases accounting for about 42% of the drought's severity.
The big picture: The new study updates findings from research published in 2020 that found evidence for the first partially human-caused megadrought in the Southwest, but noted that a drought in the 1500s rivaled its intensity and duration. That is no longer the case, the new research shows.
Why it matters: The research may help to answer key questions about how humans fare during long periods in space and how to protect them in a future where more people could spend more time off the Earth.
