Is humanity off the hook for California's record-breaking drought? A new federal report says the drought, "while extreme, is not an uncommon occurrence for the state," and is the result of natural weather patterns instead of man-made climate change, reports USA Today. NOAA researchers say a major cause of the drought has been a warm, dry, high-pressure ridge over the eastern Pacific and western US that has blocked precipitation—and climate models say greenhouse gases should have the opposite effect, causing slightly more precipitation in the region instead of blocking it. "The report is not dismissive of global warming at all," an NOAA meteorologist and study co-author says. "At the same time, drought is not a consequence of the warming planet to date."
But scientists not involved with the study accuse the NOAA researchers of failing to take into account how warmer temperatures aggravated the drought, including causing more moisture to evaporate from the ground. The report "completely misses any discussion of evapotranspiration and the increased drying associated with global warming," a climate scientist at the National Center for Atmospheric Research tells NBC. The scientists are even unable to agree on how bad the drought is, the AP reports: A study co-author says it doesn't rank among the five worst in the state's history, but a separate study released this week says it's the area's worst in 1,200 years.