The only thing that "An Inconvenient Truth" proves is that Al Gore is still an idiot. These "unchallenged" experts are unchallenged because a response to their inane hypotheses is generally beneath real science. This is mostly false science folks. The greatest source of greenhouse gases - CO2 - is people, we exhale it and unless you're willing to start sacrificing your brethren to save the world, there's not a darn thing to be done. We've heard how the world was going to end as the result of man for more than 50 years. Fools publish a time line for their doomsday and when the time passes, nothing has happened. "An Inconvenient Truth" is just another vehicle with which a disingenuous faction of American society can peddle their poop.<br /><br />And as to Al leaving the tobacco business because of his sister's death from cancer, that is a load too. Al couldn't run his farm any better than he could run the country. He was losing money on the operation because he didn't care to farm when he could make more $ on speaking tours. The only global warming that is unchallenged is the hot air produced by this gasbag!