Since I'm at Scripps Institution of Oceanography (one of the leaders in climate science), and one of the scientists in the aforementioned NOVA episode has his office about 100 meters from mine, I feel compelled to chime in (briefly) on this one.

It has certainly been more than two or three years since a scientific consensus about the reality of global warming was reached. Research into climate change (natural and anthropogenic) was prevelent by the early 1980's. Even before 1960, people like Dr. Charles Keeling (formerly of SIO) were monitoring the climate. His 'Keeling Curve', showing CO_2 levels atop Mauna Loa, Hawaii, is very well known and shows the increasing CO_2 levels in the past several decades. Of course, our knowledge of the Earth's climate increases all the time.

While there is scientific consensus about the reality of global warming, it is important to realize that climate scientists do not know everything, and there are points on which scientists disagree. Models are only as good as the theory behind them and the observations driving them, and two models can give very different results. (We can't even get the weather for next week right...think about how hard it is to figure out the global climate in 50-100 years.) Disagreement at this level is how science works. Various hypotheses are formed, tested, and upheld or rejected. With time, some hypotheses become so strongly supported by observation, theory and experiment that they rise to the level of scientific theories, which are, for all intents and purposes, facts.

It is a pity that larger acceptance of climate change as reality has taken so long. There is a problem, particularly in the US, of the general population refusing to accept what is considered to be scientific truth. The source of this problem, I believe, lies both with the public _and_ the scientists. As scientists, we certainly have a long way to go in communicating our findings beyond our small community. With that in mind, interested parties might wish to take a look at http://www.realclimate.org. I'm not affiliated with it, but it has proven to be a good source of scientifically accurate information and discussion. (Please note that controversial subjects are brought up, sometimes dealing with politics and science, so beware.) Also, a recent issue (perhaps the most recent issue) of Vanity Fair had a fun article showing the effects of sea level rise on areas like Martha's Vineyard (a classic sailing place, and hangout of Kennedy's et al.) and the Hamptons.