Green parties developed out of a wave of radical social activism, especially the student protests of the 1960s and the antinuclear movement of the 1970s and 80s.Their entrance into mainstream politics, especially in Europe, gave them significant influence but revealed divisions over nonviolence, energy policy, and economics.Greens are now seeing their support grow in many countries as climate becomes a top issue among voters, but the implications for the future of global politics are unclear.