The problem with the theories of anthropomorphic global warming is that the models don't predict future observed events. They also largely ignore historic weather events which occurred before systematic temperature records began about 135 years ago. Finally, we have less than 30 years of experience with all global climate models because we didn't have the computing power to run predictions for such complex models before about 1985. Here's a link to a description of the climate over the last 18,000 years. See what you've been missing.
Obama says that 99.5% of climate scientists think controlling CO2 emissions is important. The original paper this figure is based on, by John Cook, has been completely discredited by reviewers, including reviewers who accept the thesis of anthropomorphic global warming, AGW. See Professor Richard Tol's blog entry about Cook's paper:
Professor Tol accepts AGW. See