The big changes have to come from governments, industry and corporations. The other major area is convicing developing nations to go the more expensive or intensive route for eco and climate friendly solutions thus skipping "their turn" going through the old school profiteering and polluting industralisation developed nations did/do. If only governments would spend money on foreign development in the same way they do defense budgeting. You'd have far more allies and less fighting for territory or resources if countries and populaces could sustain themselves.
You can do a bunch personally and locally but big impact wise voting in the pro-climate based political parties and buying from your choice of products and produce manufacturers/providers are about as good as you're going to get. Install solar, reduce red meat, resuse/recycle/reclaim, use grey water, install a water tank, avoid plastic as much as possible, plant trees and bushes in your yard etc. Volunteer for local tree planting days and donate to good causes where you know the money is put into use and not just absorbed or distributed to other charitable purposes you didn't sign on for. Buy locally for your needs instead of the large corporations e.g. farmer markets over supermarket chains. Shop local strip shops over shopping malls etc.
In essence get back to a simpler life where you can. It's not just for you but your future generations.