Some people are clearly doing less nothing: there are activists protesting, formal political action groups, scientists doing research, etc. What isn't as clear is whether any this can actually overcome the huge social and economic structural issues to actually make a dent.
When I was initially thinking about my personal impact to this, the first thing that came to mind is air-travel. I don't travel much, maybe once a year to see family. I have some friends who fly several times a year to "see the world", being well-traveled is a part of their personality. But I think I may be wrong on flight being a significant contribution. My guess is that we probably all contribute to this mainly through our SP500 index investments, which financially supports a number of companies that directly contribute to global warming. We're "voting with our dollars" as they say. Maybe we can all start picking individual stocks based on environmental values/promises, and less short-term gain. Somehow, I don't think it'll happen.