It's embarrassing to admit, but we finally got around to watching An Inconvenient Truth last night. The movie, based on a multi-media presentation that Al Gore has been giving for several years, makes a convincing case that global warming has begun and will worsen. The movie also portrays Gore in a very sympathetic light, with a light-heartedness and a genuine passion that were largely AWOL during his 2000 campaign. It's easy to see how the film won an Oscar in the documentary category. It's also easy to see why the film gives the oil lobby, coal lobby, and their apologists fits.
The movie builds its case regarding global warming brick by brick. The case isn't based on just one or two statistics but rather on a stack of evidence. Conservative commentators have tended to pick apart selected examples here and there, such as that one of the dozen or so examples of retreating glaciers might be caused by some natural process other than global warming. However, there are just too many pins to knock down, and the case as a whole holds up. My guess is that at least a few people who start the movie as skeptics will have their minds changed by the end, which is about the best that you can hope for when making an argument.
The movie begs the obvious question of what are the next steps. Making the case for global warming isn't the same as making the case for specific policy actions. Conservatives are correct when they point out that some bad policies, such as the current corn-based ethanol boondoggle, are worse than no policies at all. Nevertheless, it does look like there is some low-hanging fruit here.
A first sensible start would be to make people aware of how individual actions like driving over the speed limit, leaving appliances on in stand by mode, and excessively cooling or heating a house contribute to the problem. A second sensible action would be to begin eliminating the billions of dollars of government subsidies to fossil fuel companies.
I suppose that people can argue about anything. But encouraging voluntary conservation and ending subsidies for harmful activities seem like rational starts.