Scientific American March 2004 [antikvár]

^ SA Perspectives The Climate Leadership Vacuum If you still doubt that global warming is real and that humans contribute to it, read the article beginning on page 40. Its author, James Hansen of the NASA God-dard Institute for Space Studies, is no doomsayer. Instead of relying on just computer climate models, which skeptics don't trust, Hansen builds a powerful case for global warming based on the geologic record and simple thermodynamics. He sees undeniable signs of danger, especially from rising ocean levels, but he also believes that we can slow or halt global warming afford-ably—if we start right away. Politically, that's the rub. As time slips by, our leverage over the problem melts away. Even small reductions in gas and aerosol emissions today forestall considerable warming and damage in the long run. In our view, the international community needs a leader, but the obvious nation for the job still has its head in the sand. President George W. Bush's administration implies that it will get more serious about global warming after further years of study determine the scope of the problem (tick tick tick ). The Kyoto Protocol is the most intemationally acceptable approach to a solution yet devised. Largely at the insistence of American negotiators, it adopts a market-based strategy. Nevertheless, the White House in 2001, like the U.S. Senate in 1997, rejected the treaty as economically ruinous and environmentally inadequate. The administration has yet to propose a workable alternative. Two years ago the president committed the country to reducing its greenhouse gas "intensity"—the emissions per unit of economic output—by 18 percent DIESEL SOOT is worth chasing. in 10 years. But he has not enunciated a clear and credible strategy for doing even that. The White House boasts of the $4.3 billion budgeted for climate change-related programs in 2004 as well as its backing for hy-drogen-based energy. But those initiatives don't set any goals by which they can be judged. All they do is throw money at new technologies in the hope that businesses might eventually adopt them. In other areas of environmental policy, the administration insists on cost-benefit analyses—but not for climate change policy. A real action plan is feasible. Current technology can stop the increase of soot emissions from diesel combustion at a reasonable cost. Reductions in airborne soot would boost the reflection of sunlight from snow back into space. Minimizing soot also directly benefits human health and agricultural productivity. Suitably controlling greenhouse gases is a greater challenge, but it can be done. Kyoto establishes a cap-and-trade program for carbon dioxide and other emissions. The administration has favored programs to trade credits for industrial pollutants such as mercury. Carbon dioxide is an even more appropriate subject for such an effort: creating environmental mercury "hot spots" raises local health risks, but concentrating carbon dioxide production is harmless. The expense of reducing carbon dioxide could be kept low by letting the marketplace identify cost-ef-fective ways to meet targets. Domestic emissions trading for sulfur dioxide under the first Bush administration was highly successful. Output levels were cut ahead of schedule and at half the expected cost. The only significant U.S. activity in carbon dioxide trading now is at the state level. Ten northeastern states have established a regional initiative to explore such a market. Meanwhile the administration sits on the sidelines. That's not good enough: it needs to show specific, decisive, meaningful leadership today. THE EDITORS [email protected]