George Will's Confusion

George Will again demonstrates his confusion about the topic of global warming, once again on the well-read pages of the Washington Post:

Minutes after Gore said that "the debate in the science community is over," he said "there is a debate between the American ice science community and ice scientists elsewhere" about whether the less-than-extremely-remote danger is a rise in sea level of a few inches or 20 feet . And he said scientists "don't know what is happening" in west Antarctica or Greenland. So when Gore says the scientific debate is "over," he must mean merely that there is consensus that we are in a period of warming.

This is not where debate ends but where it begins, given that at any moment in its 4.5 billion years, the planet has been cooling or warming. The serious debate is about two other matters: the contribution of human activity to the current episode of warming and the degree to which this or that remedial measure (e.g., the Kyoto Protocol) would make a difference commensurate with its costs.

The global warming debate is not really about the contribution of human activity to the current episode of warming. Current warming (~1°F) has been small and not of great consequence. The debate is about how much the globe is going to warm (and the climate is going to change) over the next several decades as a result of the greenhouse gases we're putting in the atmosphere. In other words, it's about the climate sensitivity--how much warming will take place with a doubling of GHG levels. In other words, it's about whether you believe certain gases that humans emit are greenhouse gases or not. In other words, it's about whether you think natural greenhouse gases have made the planet hospitable to human life and how much change you think increasing these gas concentrations by 30% or 100% is going to make. You can say it won't make any change, but you have to defend that idea in light of the ~33°C difference that GHGs make in the background temperature.

The debate isn't really about present amount of warming, which is, let's face it, difficult to break out into natural vs. manmade warming. Scientists think most of it is due to manmade factors. But it's the future where the debate lies, and it's the warming potential of GHGs about which you have to lay out your opinion. That's the debate.