CO2 = Pollution. Now What?

By Andrew C. Revkin

It’s nearly official. Carbon dioxide, the bubbles in beer, is a pollutant in the context of the Clean Air Act, the Environmental Protection Agency proposed on Friday. The long-lived heat-trapping gas, while benign in a brew pub, is deemed a threat to public health and welfare through its growing impact on climate and, in the long run, sea levels.

Environmental campaigners and many climate scientists had long pressed for this action. But the question now is, will it matter? First come the lawyers, poised to sue should any regulations emerge that are perceived as too costly or too weak. (Lawyers on the climate issue are undoubtedly as numerous as the climate lobbyists recently tallied by the Center for Public Integrity).

Then there’s the global nature of global warming. Molecules of carbon dioxide spewed by a taxi cab in Beijing or a power plant in Boston mix freely in the atmosphere, adding to global-scale heating in the long haul. And nearly all of the projected growth rates in emissions of carbon dioxide (and five other kinds of heat-trapping gases included in the determination) in the next few decades are expected to occur in fast-growing developing countries, led by China and India (which by midcentury is expected to be have more people than China and even today has the population density of Japan).

[INSERT, 4/18: Then there's the continuing debate over whether dealing with carbon dioxide as a traditional pollutant (regulate and it will go away) is the way to make this particular emission go away. The transition from deeply rooted energy systems based on burning fossil fuels to new norms emitting ever less of this gas -- here and in China -- is seen by many as requiring a sustained energy quest including much greater direct government investment on the frontiers of relevant technologies (batteries, photovoltaics, superconductivity, photosynthesis).]

While the Endangered Species Act is applied to species both inside and outside United States borders (polar bears and North Atlantic right whales, for instance), the Clean Air Act has no applicability to sources of emissions elsewhere.

As John Broder wrote recently in The Times, it’s likely that the move to apply the “pollutant” label to these gases is aimed at adding pressure to congressional efforts to write new gas-limiting legislation. Our new “Room for Debate” blog has a fascinating exchange of views on how, or whether, greenhouse gases should be restricted. (Keith Johnson has some useful background over at the Wall Street Journal.)

Over all, carbon dioxide and climate remain a very tough fit for the legislative and legal arenas. This reality was on display during Supreme Court arguments in November 2006 that laid the legal foundation for today’s announcement. Confusion arose over which layer of the atmosphere was the repository for smokestack and tailpipe emissions of carbon dioxide. James Milkey, assistant attorney general of Massachusetts, corrected Justice Antonin Scalia, saying: “Respectfully, Your Honor, it is not the stratosphere. It’s the troposphere.”

“Troposphere, whatever,” Justice Scalia replied. “I told you before I’m not a scientist.” Over a brief flutter of laughter from observers, he added, “That’s why I don’t want to have to deal with global warming, to tell you the truth.”

It looks like the courts will have to deal more with global warming in the months and years to come.

http://dotearth.blogs.nytimes.com/2009/04/17/co2-pollution-now-what/