Man may be causing himself a lot of discomfort; and, who knows, perhaps he will ultimately do himself in with his own behavior. I really don't know what to believe, because the evidence is so diverse on every side of these environmental issues. Bur, a very wise friend of mine once commented: "Human Beings are like a bunch of fleas on the back of a VERY big dog." Doesn't cause much damage, but it does cause a lot of itching and scratching. My guess is the planet will afterall come out of all this just fine.