Human-caused global warming has worsened California's extreme four-year drought by as much as 25%, says a new study that is just the latest to link the abnormally dry conditions with human-caused climate change.
The study by Columbia University's Lamont-Doherty Earth Observatory, published on August 20 in Geophysical Research Letters, suggests that within a few decades, continually rising temperatures and resulting moisture losses will push California into even more persistent aridity.