The European Union is experiencing a green wave, and Jesse Klaver is a major force behind it. In his four-year tenure as the leader of GroenLinks, the Dutch Green Party, Klaver has nearly quadrupled the party’s representation in the Dutch Parliament and helped pass a landmark law that would nearly eliminate Dutch emissions by the middle of the century. “For the first time, there’s an obligation for the government not only to talk about climate change but to act,” he says. Klaver is not alone—green parties in other E.U. countries have gained momentum in recent months—but the 33-year-old’s legislative success has made him exemplary of a bigger shift. —Justin Worland