It can be really simple to combat climate change.
Here it is: A dollar spent is a dollar that is respent many times by other people. Each time a dollar is spent and respent, it is eventually spent on something that produces carbon dioxide and pollutants. The more you spend, the more carbon dioxide you cause.
So, just stop spending or, more realistically, spend as little money as possible.
And remember, the purpose of life is not to grow the economy — that is just the brainwashing talking. If we all just quit spending so much money, we could solve the problem of global warming.