Don't go back too far now. Back just 25-30 years ago they were convinced of global cooling. Ahhhh...but I am sure we have gotten ALOT smarter since then. Don't get me wrong, I think being good stewards of our planet is VERY important. And we as humans have done a pretty crappy job of it. Just don't throw the "We can't possibly be wrong THIS time" argument out there. It could happen again.