White House spokesman Jay Carney Jan. 23 deflated environmentalists’ hope of a major federal program to counter climate change, by declaring that the “we have no intention of proposing a carbon tax.”

Carney’s statement is a letdown for progressive climate-control advocates, who say the federal government has the regulatory and taxing power to try to affect the globe’s temperature by curbing the release of carbon dioxide from cars, houses, factories, power plants.

On Jan 9, Vermont’s Sen. Bernie Saunders introduced a bill that would levy a tax on companies that generate carbon dioxide. The bill is unlikely to pass, partly because economists argue it would further burden the nation’s slow growing economy.