If a plastic bottle takes 450 years to biodegrade, that isn’t so bad. 450 years and, poof, things are back to normal again. Only 10-20 years for plastic bags. I thought it was going to be longer. Seriously. If we stop mass logging and fishing for 80 years or so, I think the world could fix itself. No idea about nuclear waste though. It seems to last way too long to fix.