In May, President Obama announced that his administration would set new, nationwide standards for vehicle fuel efficiency in order to reduce tailpipes’ contribution to global warming. The administration said it would use a plan developed by the state of California as a model.

The announcement appeased environmentalists and the California government, both of whom wanted the stricter standards. The auto industry also jumped on board, because it wanted one standard applied to all 50 states.

But since then, we’ve heard nary a whisper from the administration about when these new standards would be formally proposed, finalized, or made effective.

That changed Tuesday, when EPA sent a proposed rule titled, “Control of Greenhouse Gas Emissions from Light-duty Vehicles” to the White House Office of Information and Regulatory Affairs (OIRA). OIRA will review the draft proposal, share it with other federal agencies, and suggest edits. Since the president himself promised to enact emissions controls, OIRA is almost sure to sign-off on the proposed rule.

As Frank O’Donnell at the Blog for Clean Air points out, the movement on the vehicle emissions rule signals that EPA may be nearing completion on its final rule declaring greenhouse gases a threat to society. The two rules are related because, under the Clean Air Act, once EPA says that a pollutant is a danger, it is obligated to regulate it.

O’Donnell also says that these regulatory developments may prod the Senate to work on cap-and-trade legislation when it returns from summer recess:

The review suggests that EPA is nearing a final “endangerment” finding that global warming emissions threaten health and the environment. That decision – the right response to the big Supreme Court decision on global warming – may be interpreted by some as a polite reminder to the Senate that it cannot ignore the climate issue. The EPA finding could be the starting point for additional administrative action on climate if the Senate fizzles.