Can anyone guess which branch of the US government produced the following paragraph?
"A well-documented rise in global temperatures has coincided with a significant increase in the concentration of carbon dioxide in the atmosphere. Respected scientists believe the two trends are related. For when carbon dioxide is released into the atmosphere, it acts like the ceiling of a greenhouse, trapping solar energy and retarding the escape of reflected heat. It is therefore a speciesthe most important speciesof a 'greenhouse gas.'"
Glosses make this statement typical of arguments for urgent responses to global warming. The paragraph thus might seem to belong to some political document, most probably issuing from Congress or, perhaps, an agency of the Executive Branch.
But no, the Judicial Branch served up the delicacy. It appears atop the Supreme Court's Apr. 2 opinion that CO2 should be subject to regulation as a pollutant under the Clean Air Act.
Supreme Court justices are busy people. Their spacious minds brim with legal knowledge and arguments about the many complex cases awaiting their decisions. To them, it probably seems unimportant that observed warming hasn't always coincided with the Industrial Age's CO2 build-up, that temperature averages in fact fell for many years while the gas concentration rose.
The justices also might consider it inconsequential that CO2, a life-sustaining compound of which human activity is hardly the only source, is less important as a greenhouse gas than water vapor.
Yet pesky trivialities like these, which supporters of aggressive CO2 regulation ignore, lie at the center of arguments over what to do about global warming.
If average temperature and CO2 concentrations haven't changed together consistently, for example, the gas build-up can't account for all observed warming. It might therefore be impossible to influence global average temperature much with cuts in emissions of a relatively small portion of one gas among several. Controversy about this, notwithstanding senseless talk about scientific "consensus," is lively.
And their honors have taken one side in a political issue of the type that the Constitution seems at pains to reserve for other branches of government.
(Online Mar. 6, 2007; author's e-mail: email@example.com)