Depending on one's perspective on climate change, last week's events provided either a series of predictable disappointments or a temporary breather, before our expected plunge into a world of constrained emissions. The statement on climate change from the G8 Summit in Hokkaido, Japan, and the subsequent "Major Economies Meeting" reflected only incremental progress since 2005's Gleneagles G-8 meeting and last year's Bali Climate Conference. And although the announcement that the EPA would effectively defer regulating greenhouse gas emissions under the Clean Air Act until the next administration was overshadowed by allegations that Vice President Cheney had interfered with Congressional testimony on the health risks of climate change, the former should not have shocked anyone. On the heels of the latest failure of US cap & trade legislation, it was not in the cards for 2008 to be more than a transition year for action on climate change, and that view has been borne out.
Lacking the time or space to comment on all of the implications of these actions, I'd like to focus on the principal complaint I've seen concerning the G8's contribution, to the effect that their stated target of cutting global greenhouse gas emissions in half by 2050 falls far short of what would be necessary to stabilize the climate. I would suggest that at this point setting any global emissions target and then starting to work towards it is more important than the absolute level of the goal. Stabilizing atmospheric concentrations of CO2 and other greenhouse gases at their current level would apparently require reductions on the order of 80%, but whatever target we set now for 2050 is unlikely to be the last word, and even more unlikely to be achieved with precision. We will ultimately either undershoot, because global emissions are now growing so rapidly that it will take longer and cost more to halt and reverse this trend than we hope, or we will overshoot, because the world will change so much in the next 42 years that a 50% reduction will prove to have been ridiculously timid.
Consider 1966, removed from us by the same interval as the world of 2050, and the sorts of predictions that were then current regarding the 21st century--predictions rooted firmly in the dominant technologies and institutions of the day. By now all air travel should take place in sumptuous luxury aboard supersonic aircraft. Rather than lumbering along with gasoline engines, our cars should zoom down the roads on nuclear batteries and occasionally even fly. Recessions and credit crises should be a relic of the past, as gigantic mainframe computers guide the economy with total accuracy. And don't forget the colony on the moon. For good or ill, we didn't get those outcomes. Instead, we got ubiquitous real-time information and communications via wireless PCs, cellphones and the Internet, and the beginnings of unprecedented medical and materials revolutions based on DNA-level biotech and nanotechnology. In addition, the world's population has grown by about a half billion fewer people than once expected, making some of our current problems less severe than they would have been. I see little reason to conclude that the next four decades will be any less surprising and prediction-thwarting than the last four. That doesn't mean we should punt on climate change and wait for a miracle, but it does suggest that focusing our first steps firmly on the next 10-20 years makes more sense than bogging down in arguments about a longer-term future we can't forecast.
Few things about climate change are certain, including the level of our emissions in 2050. However, at this point we do know that the roadmap set forth in Bali last December, and resting on the findings of the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, continues to guide the negotiations on a new global climate agreement. Although the shape of the ultimate compromise between the developed and developing economies--the sine qua non of a meaningful successor to the Kyoto Protocol--remains unclear, the key parties at least seem to be willing to tackle it. And we know that on January 20, 2009, a new US administration will take office with climate change as a top priority from day one.