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Most major droughts have tended to happen on seasonal or yearly time scales (范围), resulting from variability in large-scale climate patterns such as El Nino. But in the last six decades, there has been a transformation to more droughts that form over just a few weeks in most of the world, researchers of a new study at Nanjing University of Information Science Technology report in Science. This finding has implications for ecosystem conservation and agricultural management.

Some flash droughts develop into seasonal ones, yet even those that do not can cause significant damage to agriculture and contribute to other extreme weather events such as wildfires and heat waves. In the summer of 2012, a severe flash drought across the United States caused over $30 billion in damages. Flash droughts happen two to three times as often in wet regions such as northwest North America, Europe and southern China as elsewhere. Many affected areas transformed from normal conditions to extreme drought within a month,and no climate models predicted it.

As the world continues to warm, causing less rainfall,flash drought frequency is expected to continue to rise. Droughts can happen and strengthen rapidly, but current monitoring systems often cannot catch their beginning on short enough time scales. That makes flash droughts a sort of a hard nut, the researchers say.

“We have to improve these systems,” the lead researcher Yuan Xing says, “by exploring the mechanisms behind flash droughts,perhaps with the help of artificial intelligence.” Dealing with these droughts isn’t just about having a better tool set, Mark Svoboda, who first coined the term “flash droughts”, believes, but also a different mind-set. “It is human nature not to deal with drought until you’re in it. We advocate that drought be dealt with ahead and actively.”