[jfengel]

As nikhilsimha says, you can vote.

Nothing you do yourself matters. It's not about what you do as an individual, because your choices are constrained by the large scale infrastructure.

Giving up your car means little, but voting for a vast upgrade to public transportation means a lot. So does voting to redesign the way we build cities and suburbs, because our current streets and zoning are laid out for the assumption of cars.

Reducing your meat consumption means little, but changing the agriculture subsidies makes a difference. Your own habits are a microscopic signal; to shift the economics of it requires a collective reconsideration of who we are -- away from "we are the nation of people who don't eat meatless meals".

Right now those things aren't even on the ballot, because they're hard, and even people who accept climate change are afraid of getting massacred for even suggesting that something hard might be in order. Which is why the #1 thing you can do is send the message: "I will not vote for you if you deny climate change. Belief in science is my top priority and I'm not going to accept your conspiracy theories."