Climate activists have tried marching and lobbying. Now, a growing flank of movement radicals want to take more extreme action. Author Dana Fisher tells us who they are, and sociologist Matthew Wolfe traces the history of radical environmentalism in the US.

Today's episode was produced by Avishay Artsy with an assist from Siona Peterous. It was edited by Miranda Kennedy and fact-checked by Jon Ehrens. Our engineer is Patrick Boyd.

Transcript at vox.com/todayexplained

Support Today, Explained by making a financial contribution to Vox! bit.ly/givepodcasts

Learn more about your ad choices. Visit podcastchoices.com/adchoices

Gladiator: realidad y ficción