Environmental Protection Agency (EPA) chief Lisa Jackson extended an olive branch this week to lawmakers who are pushing to block her from regulating carbon emissions in the absence of a congressional climate bill, but Jackson’s promise to delay action until next year appears to have made no headway with Republicans and coal-state Democrats. 

Carol Browner, at right, with the president. (Photo: TreeHugger)

If Congress succeeds in blocking the EPA from following through on a Supreme Court mandate to regulate emissions, a legislative path to nationwide pollution limits would effectively become the sole means for the Obama administration to follow through on commitments it made at last year’s Copenhagen climate summit.

But White House climate adviser Carol Browner noted today that a congressional block on the EPA’s authority would have a second wave of consequences for transportation policy — it would jettison the Obama administration’s much-heralded deal to raise auto fuel-efficiency standards to 35.5 mile per gallon by 2016.

"I don’t know why members [of Congress] would want to go out and vote against the science of climate change," Browner told attendees at a climate conference sponsored by The New Republic.

Without EPA authority to regulate emissions under the Clean Air Act, she explained, "there is no car rule" — referring to the agreement to adopt California’s landmark efficiency standards as a national model.

"If the car rule were not to go forward, California would still have all its authorities," Browner added, meaning that the auto industry’s fears of compliance with a "patchwork" of regional fuel standards would become a reality.

Browner’s comments came as climate legislation continues to lose momentum in the Senate, giving more political ammunition to lawmakers and industry representatives who seek to stall the process.

Yet Sen. John Kerry (D-MA), one of three negotiators working on a "tri-partisan" climate deal in the upper chamber, took a notably upbeat tone today on the prospects for action this year, and Browner concurred with Kerry’s sentiment.

"We’re all now playing the same game inside the same stadium," she said. "The question is, can we bring it to a successful conclusion? … We’re fully engaged in this effort."

One move the White House won’t make, per Browner, is to release its own set of specific climate proposals, similar to the health care reform plan released by the president this week. That leaves unclear the administration’s stance on several simmering environmental debates, including the share of revenue from a future climate bill that should go to clean transportation.