Proposals to cut greenhouse gases are flying around Washington like confetti in a hurricane, with President Bush tossing out his ideas in Tuesday night's State of the Union message. What's needed in this debate is full disclosure on the difficulty of the task.
Start with Kyoto. From the atmosphere's standpoint, the treaty's goal of reducing carbon-dioxide emissions from industrial countries by an average of 5 percent below 1990 levels by 2012 will barely slow the rate of increase in CO2 concentrations, even with full compliance by its main participants, Europe, Canada, and Japan. The framers knew that but felt they had to start somewhere. And those nations are now groaning over the burdens, with many not close to compliance.
Kyoto also inherently acknowledges the difficulty of simply cutting emissions. So industries are allowed to earn "credits" if they pay for "green" energy projects elsewhere. But even that global enterprise has many difficulties.
In the US, meanwhile, some noble attempts to tackle global warming are proving awkward. The University of Colorado, for instance, plans to shut down an old gas-fired cogeneration plant that provides both steam and electricity for its Boulder campus. But while it will build a new gas-plant just for steam, it has to buy electricity from a coal-burning utility – increasing CO2 emissions, even as the city of Boulder tries to meet emissions goals.
Public opinion may have shifted toward acting on global warming, but people haven't fully grasped the uncertainties, costs, and difficulties. That leaves the debate vulnerable to wild claims of either pain or painlessness in taking steps to curb emissions.
One bit of uncertainty stems from the absence of a true climate policy. That may sound odd as lawmakers and the president go head to head on their proposals. But the federal government has not set a desired endpoint for reducing carbon-dioxide concentrations or for slowing the increase in global temperatures.
Choosing such endpoints, and estimating the cost of achieving them, won't be easy. There are still ample unknowns about the future pace of climate change. (Greenland's ice cap, for instance, is losing mass faster than scientists said it would a few years ago.)
One well-understood science is the carbon cycle, so it would be easy to pick a target for lower CO2 concentrations. But that may miss a whole range of other processes that are less well understood than the carbon cycle but which also influence temperatures.
Another uncertainty is the course of technologies tapped to reduce emissions. A certain rate of innovation is expected by the Intergovernmental Panel on Climate Change (IPCC). Without those innovations – which are driven more by market forces than climate policy – the IPCC concludes that emissions would be roughly 10 times their current levels. So the low-hanging fruit already is being picked. Congress may need to offer hefty incentives or impose costly penalties to achieve faster reductions.
But Congress can't go down that path out of blind panic. It is, in effect, asking Americans to buy an insurance policy. Its provisions must not be driven by polls or hyperbole, but by sound science and a careful regard for the remaining unknowns.