As noted by a Daily Kos diarist the CBS program "60 Minutes" deserves considerable credit for being willing, in a story about global warming, to report the scientific facts and the opinions of those most knowledgable about the phenomena, rather than feeling compelled to offer the opinions of crackpots whose opinions on the matter are grossly outside the scientific mainstream to provide "balance".
Sometimes there are legitimate differences of opinion on issues. Often, especially in science, there aren't. When there are legitimate differences of an opinion, it is not "fair" to present a crackpot view simply to get another side of the story. Even when their are legitimate differences of opinion, the press should always report, at least, three perspectives. The respective opinions of the people who disagree, and the facts that are known, which can often cast light on whose opinion is more sensible.