Climate change is inherently large scale. There's nothing that will change that.
We can change the equation only by large scale "contracts" and the like. That generally means governments. For instance, we can vote for representatives that make laws that limit emissions from factories and vehicles, and make treaties with other countries. Those things are not subject to tragedy of the commons.
I am not advocating for "messing with the atmosphere" in this sense, but I'm also not rejecting it outright. We are already messing with the atmosphere on a large scale, due to billions of individual decisions driven each one of those individuals' self-interest. If you are going to mess with it, I'd rather it done based on a controlled methodology based on science.