I have to be humble about this, as I do with all issues where I'm not the expert, and say that I don't know. I grew up with a father who pushed a lot of right-wing dogma on me, a lot of conspiracy theories, etc. As I've gotten older, I've been exposed to the other viewpoint (which I wasn't, as a child) and have changed my position on several issues. On this issue, I have to defer to the scientists. The experts are the ones who know what's going on, so I have little choice except to accept what they say. I would compare this to a mechanic fixing my car: one mechanic may make the wrong diagnosis, just like one scientist may make the wrong conclusion, but when you have a consensus among the most reputable mechanics (scientists) in the country, I accept their diagnosis on my car because I'm not a mechanic and I have no idea what's wrong or how to go about fixing it. I grow nervous around people who are not reputable scientists that make bold claims about science that contradict the claims of hundreds of reputable ones.
That being said, I have two other thoughts on global warming and the environment:
1) As Christians, we ought to be good stewards of the earth. We ought not mistreat any part of God's creation, so the message of caring for the earth that is promoted by environmentalists is, I think, in line with a biblical world view. As with anything, it can be taken too far, but most of the time the ones who try to poo-poo environmental protection are groups like the oil companies--who are more interested in money and power than they are for the care of the earth.
2.) If global warming turns out to be bogus and we take all these steps to change our way of living and come up with cleaner ways of producing energy, we still win. Cleaner air, cleaner water, more fuel-efficient vehicles, and all the rest are advantages for humankind.
