When Disaster Strikes, Is Climate Change to Blame?

Last November the spring weather in South America jumped from cold to searing. Usually at that time of year people would have been holding backyard barbecues, or asados, in the lingering evening light. But on December 7 the temperature in northern Argentina, near the borders of Bolivia and Paraguay, hit 115 degrees Fahrenheit, making it one of the hottest places on Earth. The heat exacerbated a three-year drought, baking the soil and shriveling vast wheat crops before harvest.

As the Argentine government restricted wheat exports and warned people to stay indoors, a small team of scientists from around the globe logged on to Zoom. They belonged to the World Weather Attribution (WWA) group, a collaboration of climate researchers that Friederike Otto and Geert Jan van Oldenborgh formed in 2014 to address a persistent, nagging question: Is climate change making extreme weather worse and, if so, by how much? The group’s ambitious goal is to provide straight answers almost as quickly as disasters strike—for the public, the media and policy makers, as well as for emergency managers…