Although efforts to revive climate legislation are under way in the Senate, odds of enacting a bill to curb greenhouse gases remain quite long.

Not to worry, though. Didn’t the Obama administration say that in the absence of such legislation the Environmental Protection Agency would impose limits on carbon-dioxide and other greenhouse gases?

Don’t count on it.

The fossil-fuel lobby – which as spent more than $100 million to derail effective climate change policy – is no doubt delighted with two measures pending in the Senate that would prevent the EPA from regulating greenhouse gases.

We’ll start with the bad and move to the worse.

Earlier this month, West Virginia Democrat Jay Rockefeller IV introduced a bill (S. 3072) that places a two-year moratorium on the EPA’s authority to place new restrictions on utilities and industries that emit large quantities of CO2. The biggest sources of CO2 are utilities that burn coal. Little surprise, then, that a senator from West Virginia – one of the biggest coal producers – would author such a bill.

What’s interesting is that West Virginia’s other senator, Democrat Robert Byrd, has declined to support Rockefeller’s bill:

“I do not plan to co-sponsor Sen. Rockefeller’s legislation at this time. I was encouraged by the response last week from EPA Administrator Lisa Jackson… that [EPA] would delay until next year the application of stronger standards regarding increased efficiency or reduced pollution at large power plants and factories.”

Rockefeller’s bill – at least for the time being – has lowed momentum on a more onerous measure proposed by Sen. Lisa Murkowski (R-Alaska). Murkowski introduced a resolution of disapproval (S.J. Res. 26) that would nullify the EPA’s endangerment finding on greenhouse gases and permanently strip the EPA of its authority to regulate CO2. Unlike Rockefeller’s bill, Murkowski’s measure is permanent and would also stop the EPA from limiting all sources, including cars and trucks.

The decision by the EPA to move ahead on regulating GHGs is not some arbitrary power grab by the executive branch. In a 2007 decision, the Supreme Court ruled that the EPA had a mandate to regulate greenhouse gases as a pollutant. Last year the EPA initiated a scientific review, which concluded that CO2 and other greenhouse gases pose a threat to the health and welfare of the nation. With this endangerment finding, the EPA was obliged to develop new rules regulating GHGs, which were announced late last year.

EPA Administrator Jackson is the first to say that comprehensive climate legislation would be better, more effective and less costly. But in the absence of such legislation – with the clock still ticking on climate change – EPA regulation is the only backstop we have to apply the brakes on CO2 emissions and prevent a bad situation from getting worse. And the threat of EPA rules has provided a strong incentive for Congress to enact legislation. Should the EPA be stripped of this authority, that incentive vanishes and a signal is sent to the rest of the world that the U.S. will continue to drag its feet on climate change.

Citizens Climate Lobby is asking its members to contact their senators to oppose both the Rockefeller bill and the Murkowski resolution. You can join in this action by going here.

Should these measures in the Senate – and seven others like them in the House – be defeated, the pro-carbon lobby has another ace up its sleeve: Negotiations are happening, according to 1Sky, with senators John Kerry (D-MA), Lindsey Graham (R-SC) and Joe Lieberman to gut the Clean Air Act in new legislation soon to be unveiled.

More about that next time.