My biggest criticism of the Church of Global Warming (Praise Gaia and her anointed prophets the Goreacle and Tom Brokaw. Hah-men!) is their denial, or, at best, their omission (but a lie of omission is still a lie), that Global Warming is a natural event. Two recent peer reviewed studies (those valued most highly by the faithful unless it's about the health risks of marijuana) show that Global Warming can occur in the absence of Man.
First: Scientists from NASA say that Mars has warmed by about 0.5°C since the 1970s, which is about same amount of warming experienced on Earth over approximately the same period. To me, this suggests that Global Warming may be a natural phenomenon over which we have no control. No amount of florescent light bulbs replacing incandescent will stop it.
Second: Greenland volcanic eruptions 55-61 million years ago broiled and acidified the oceans, and killed up to 50 percent of the world’s deep-sea organisms; also opened up new migration routes for horses and other mammals into North America; and might have even fueled early primate evolution, the study says by raising global temperatures about 10°C. The study said it took roughly 100,000 years to peak, and another 100,000 years or so for the climate to recover. To me, this suggests that Global Warming may be something best measured in geologic time.
Yes, the second article does say we may, not will--but may--cause the process to take 100 years instead of 10,000. But the first article suggests that Global Warming is occurring at the same pace on Mars, where we aren't.
Does this mean we should stop recycling, increase greenhouse gases, and continue drinking bottled water? No. We have an obligation to share resources. Does it mean we have to completely change our lifestyle by political means, including passing legislation requiring everyone in the US to become Vegan? No. Humans may have less of an effect on Global Warming than even I thought. Does this mean that Global Warming is primarily a political movement? Oh, yeah. It's a movement that is designed to position Al Gore for another run at the Presidency.