Global Warming; A True Threat?

Is Global Warming a real threat, or is it just a scam concocted by enviro-freaks for the pleasure of screwing the system?
I myself see it as a two way deal. The scientists ar eprobably telling the truth, but the governemtn, in all its greatness, has completly demolished the whole theory. They either take the sid eof GW Bush "It Doesn't Exist, and it never has..." or the side of Al Gore "Oh my God-Save the world...STOP GLOBAL WARMING!" The truth is, from my studies, you will NOT stop global warming, just alter it a bit. Humans have made themselves a part, albeit a small part, of the Earth System. The Earth is warming up from the last ice age anyways, thus the warming is going to naturally occur. Our effect of dumping CO2 into the atmosphere has only sped that process up. If we do curb our emissions (which, don't get me wrong, I think we should be more environmentally friendly), then the Earth will still warm up, just not as quickly and with slower, more adaptable-type results.
But then, there are those who feel otherwise...