Here is an answer to a really dumb question approvingly quoted over at Cafe Hayek:

More than a few reputable scientists see potential problems in the climate change that is occurring...For every factoid about ice sheets or sea levels or sun spots I can pull from the skeptics' literature, someone else can produce a counter-factoid. How is a nonscientist to decide which is accurate?

It's really not very hard. Much like in the debate over evolution, one side is made up of the overwhelming majority of scientists; the other is not (the wikipedia list of scientists who are global warming skeptics currently contains 16 names).