In general I think extremism is poppycock and I think it's insane to get all hyper about controversial stuff. Until recently I believed that "global warming" was a bunch of stuff and nonsense ...and in some ways I still do... but the issue is generating some good things that need doing so I'm not sure if jumping on the tree-hugging-environmentalist bandwagon is necessarily a bad thing.
I definitely believe in the National Park and National Preserve program. I think it was a great thing Roosevelt (both of them) did to create them and enhance them. I do not like that they have turned Yosemite and Yellowstone into tourist spots where the natural beauty has been altered to the point of near destruction (some parts are destroyed, the natural beauty and wildlife that once lived there is gone completely).
Some articles I have read recently discuss the impact of humans on nature. This article talks about Greenhouse Gasses. Those are the bad ones. Those are the ones created by the burning of fuels and the resulting toxic gas is released into the atmosphere and causes a "warming" effect.
Another article I read discusses the ozone layer, which was a big hulla-baloo when I was a kid, and how the whole is getting smaller. This is a good thing.