Commentary: Global Warming?

I just read an interesting article arguing against man-made causes of global warming. The article, written for laymen, is available here from FoxNews.com. Since I trained as a meteorologist, I find this article to right in line with some of the data I remember observing in my classes on climate.
A large part of the increase in global temperatues sure seems to me to be due to the "urban heat island effect". This effect occurs as the result of the tendency of hard, urban surfaces to rise (and thus emit) greater amounts of heat than their rural counterparts. We all know from experience that concrete gets warmer than grass, even when the two are right next to each other. A similar thing may be happening with many of the observation stations around the world. As more people move to cities, urban areas expand, surrounding weather stations, resulting in warmer readings. The overall planet, then, may not be suffering a greenhouse effect, but rather, our observations may be increasingly inaccurate. In light of that, I would love to see more studies (open-minded ones, not ones funded by extremist environmentalist groups) on what really is going on. We shouldn't commit ourselves to economically-damaging treaties (like the Kyoto protocol) until we know for sure whether it will really do any good at all.