All this shit about capitalism vs non-capitalism in the context of environmentalism is just you assuming that a socialist state would be better environmentally than a capitalist one, but there is no reason to suppose this. I’m not an expert but I’d say the environmental record of the Soviet Union between 1962 and its dissolution was worse than that of the United States. It was dogshit, anyway.
Climate change is a tough problem because fixing it involves substantial economic pain, because its devastating effects will not become obvious until it’s too late, and because unilateral action on the part of any one government probably isn’t enough to fix it anyway. Switching the economic system to socialism won’t do anything about any of this. It’s just tough to have a democratic system and expect people to vote against their immediate material interest based on what to them is just some abstraction.