Political participation -- voting, organising for the groups you support, actively engaging in meetings and public forums, building social groups of like-minded individuals. It is hugely effective. The worst doomerism is the idea that politics is ineffective. It is incredibly effective, and only the people that participate in it have any effect on it.

There are more types of politics that national and international. Local, state/provincal, city, etc. The close it is to home the more you'll see the effects, and the more power you'll have. But accepting the supine position of "well I can't do anything" only guarantees your powerlessness. Fight for the future you want! Convince 5 people that something is important, and you're already 500% up. It scales like crazy.