Climate has been changing since the earth was born and will continue to do so despite whatever measures man kind takes to try and change this cycle. Where many of us stand in Canada right now there were 2 kms of ice over our heads thousands of years ago. Alberta used to be a a tropical waste land with temperatures matching those now in the equatorial regions of our present world. These are facts. North America was a giant ice ball. If the earth hadn't "warmed up" since then, we wouldn't even be here. Al Gore, David Susuki and climate  scientists play to the ignorance of many of us, and many of us just accept it.