Extreme events as an inadequately explored measure of solar geoengineering performance

Abstract Global mean surface temperature is the primary target used to design and compare solar geoengineering simulations and it is a useful first-order predictor of the climate response. Its limits as a measure of performance, however, remain largely untested. Studies of how solar geoengineering alters climate extremes exist yet remain inadequately explored. We argue that extreme-event metrics should become a formal part of performance assessment, so that success is judged by how interventions alter the risks of floods, heatwaves and droughts especially for climate vulnerable regions.