Data from tree rings suggest this drought is the worst in the region in 500 years
A “megadrought” gripping the western United States is the worst one in 500 years, scientists say. And it’s the first to be influenced by human-caused climate change.
A study published this week in the journal Science investigates the occurrence of megadroughts in western North America over the last 1,200 years. While a megadrought has no strict scientific definition, most studies classify them as severe droughts typically lasting a couple of decades at least—longer than any drought event that occurred during the 20th century.
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