This BAMS special report presents assessments of how human-caused climate change may have affected the strength and likelihood of individual extreme events. This is the second year that scientists have identified extreme weather events that they said could not have happened without warming of the climate through human-induced climate change. The U.S. Northern Plains and East Africa droughts of 2017, floods in South America, China and Bangladesh, and heatwaves in China and the Mediterranean were all made more likely by human-caused climate change, according to research published in the Bulletin of the American Meteorological Society (BAMS). This report presents 17 peer-reviewed analyses of extreme weather across six continents and two oceans during 2017. It features the research of 120 scientists from 10 countries looking at both historical observations and model simulations to determine whether and by how much climate change may have influenced particular extreme events.