The Soviet Union sure wasn’t capitalist by any reasonable definition of the word but still jumped from one major environmental catastrophe to another, to the point where there are still plenty of large areas to deadly to inhabit unprotected.

Even climate change wise it was effectively a petro state which relied heavily on useing and selling cheap oil at every opportunity.

I mean I may be a democratic socialist but even I admit that not everything can be blamed solely on capitalism. Even a fully democratic state operating in the best interest of its poorest people could well decide that it’s in their best interest to make thier lives better by focusing on material growth if it thought that that the consequences for its own people were minor enough.