Do a mental experiment - imagine the only form of corporation we had was a cooperative, limited to 10,000 employees. Would you expect environmental damage to increase?
I feel it takes large, hierarchical organisations, where the decision-maker is very removed from the consequences, to create this level of environmental devastation.
Now imagine we went through the 70-year long history of environmental protection and did a score:
Proactive environmental action by the government /proper authority is evidence that the current system is working, 1 point for current system. If a government only acts after mass protests or public outcry, I take that as a point for the anarchic system. If there is mass outcry, and still no action, take it as two point for the anarchic system.
If we did the score we'd have to face the fact that most of environmental laws are only on the books because of some form of public outcry or protest.
You are free to argue that anarchism would be disastrous for our standards of living or crime rates, but specifically on the point of environment, it would probably do a lot better.