Warming Targets

Climate change policy is very much in the news these days, and it's been interesting to observe the intense focus by the media and commentators on the differences among various parties on this issue: the US, EU and China; the Administration and Congress; and the states and the federal government. As a practical matter, these differences must be bridged, or at least addressed, in order for meaningful action on climate change to occur. But while these gaps can't be ignored, they shouldn't blind us to the remarkable convergence that has emerged on the broader aspects of the issue--something that seemed nearly unattainable only a few years ago. It's also worth applying a little common sense to how we regard the remaining points of disagreement.

Although last week's announcement on climate change by President Bush is seen by many as too little, too late, it is noteworthy that he now embraces the idea of a global goal on reducing greenhouse gas emissions, encompassing not just the current signatories to the Kyoto Protocol but all the world's large emitters. Unless the US and the large developing economies participate in a global effort to reduce emissions, the Kyoto process is doomed to fail, as the countries bound by it account for an ever smaller fraction of future emissions. Even the EU, which has implemented sweeping measures to manage greenhouse gases, will not meet its target to reduce emissions to 8% below 1990 levels without significant new steps. So while cynics might see the President's proposal as a gambit to undermine the mandate of the UN Framework Convention on Climate Change--under the auspices of which Kyoto was established--it is clear that the focus must now be on the post-2012 period not covered by Kyoto, and on bringing the US, China and India to the table with the EU, in whatever venue they can all convene.

The differences between the US administration and the EU are magnified by the current G-8 meeting underway in Germany. The host government, supported by other EU members, has proposed a target of reducing emissions to a level that would prevent exceeding a 2 degree Celsius increase in temperature versus pre-industrial levels. Neither the US nor China will accept such a limit, for reasons that I find eminently sensible. While the appeal of the 2 deg. target is understandable, the inertia of our past emissions and present capital stock make achieving it look like a real stretch. Even at an atmospheric CO2 concentration of 400-475 ppm, a level we look almost certain to reach within the next several decades, a variety of climate models suggest we could exceed the 2 deg. goal. That goal has other problems, not the least being that we're already about halfway there. For that matter, it's not entirely clear that it makes sense to use as a baseline a period when temperatures were rebounding from the "Little Ice Age," a real phenomenon that was not invented by deniers of global warming. A goal based either on an absolute level of emissions or atmospheric CO2 concentration seems much more useful, given the range of uncertainties in the correlation between either of those and actual temperature.

Meanwhile, a draft House bill on climate change would derail efforts by states to limit their own emissions independently of a federal target, and China continues to point to inequities in per-capita emissions as a "get out of jail free" argument on emissions reductions. Call me naive, but I don't see how we are going to get past all these differences unless we start from where we concur: the planet is warming, due in large part to our emissions, and this is a global, not a regional or local problem. That much agreement seems finally to be in place, and we ought to build on it in whatever venue will move the ball down the field.