If in the US I'd suggest getting politically active. It will take long enough even according to the pessimistic models (assuming we don't hit some doomsday scenario like the clathrate gun) for things to actually get noticeably bad [1] that a lot of people will choose short term profit over long term fixing the climate.
That means that to seriously get things done soon is going to require government action, and that means politics.
Regardless of whether you lean to the left or the right, register as a Republican and participate in the Republican primaries or caucuses for your local, state, and national offices supporting those Republicans who acknowledge that climate change is a series problem and that the government needs to play an active role in slowing, stopping, or reversing it.
I say register as a Republican, even if you would normally be something more to the left, because right now the Democrats are much more likely to nominate candidates that acknowledge climate change and the need for strong government action. The Republicans do have some people who believe that, but they currently rarely get nominated.
What we need to see is general elections where it is both the Democrat and the Republican that are on the right side of climate change so that no matter which party wins the election we get a government that will do something about the problem.
[1] Generally what most places will see is that bad things that already happen there will very slowly happen a little more often, and get a little more bad. But in many places there will also be good things that start happening a little more often and get a little bit better. It will take a generation or two before these changes have become big enough and frequent enough in most places that it will really be noticeable to the people there that yup, their climate has changed.