In anticipation of the Climate Change March planned for this coming weekend, see this article from the NYTimes: Climate Change is Now.
You can get involved politically, and you should. Participate in efforts to persuade the administration and Congress to take a different tack. Strive to elect people who take climate change seriously. But such work has a long lead time and an uncertain outcome.
In the meantime, you can do something else, as well: Look for ways to influence companies, communities, cities and states, all of which can have a big effect on the climate. In these realms, there is reason for optimism — and room to do so much more.