Earlier today, EPA Administrator Lisa Jackson announced that the agency would miss its agreed-to Sept. 30 deadline for new climate-change rules. Normally, that wouldn’t be headline-worthy. Air-pollution regulations are, after all, big and complicated. The EPA often asks for extensions so that staffers can have more time to thrash out the technical details. It’s not always a big deal. But seeing as how, just last month, the White House scrapped its anticipated ozone rules — after many months of delays and requests for extensions — any sign of toe-dragging by the EPA is likely to come in for scrutiny.

(Gerald Martineau)

The EPA says it will produce a timetable for the regulations “soon,” and that it’s not bowing to political pressure from the White House. Republicans in Congress and business groups have been fighting hard against the new greenhouse-gas rules — not least because they’ll come on top of a flurry of other Clean Air Act updates that will already force the closure of many older power plants. (On the latter, by the way, officials from the Federal Energy Regulatory Commission testified before Congress yesterday that electric utilities would be able to adjust to the rules without supply disruptions.)

But environmentalists are particularly sensitive to the possibility that the Obama administration is wavering — particularly because, at this point, EPA regulations are the only viable option for tackling global-warming pollution in the United States. A 2010 report from the World Resources Institute found that the EPA’s climate rules, when fully deployed, could cover about three-quarters of the country’s greenhouse-gas sources and reduce U.S. carbon emissions anywhere from 5 percent below 2005 levels by 2020 to a 12-percent cut. For reference, the Obama administration pledged a 17-percent cut at Copenhagen.

Other experts, however, say that the delay isn’t surprising. Jeffrey Holmstead, a former EPA official who now works as an attorney at Bracewell & Giuliani, notes that the agency has been focusing on its big mercury and air toxics rule for power plants. “It’s the same group of people working on all of these rules,” he says. “There’s no way they were going to get this one done on time.” Holmstead adds that the mercury rule — which is expected to drive the shutdown of older coal-fired power plants — would likely have a bigger impact on carbon-dioxide emissions than the New Source Performance Standards, which can mainly be used to require efficiency upgrades.

Even so, green groups have been quick to sound the alarm. “It is not clear how long a delay EPA wants,” said David Doniger, the director of the Natural Resources Defense Council’s climate program. “Taking a little more time to get it done right is one thing. Punting on its duty to protect our children and our planet would be utterly unacceptable.” Climate advocates don’t want to find themselves in another ozone-rule situation — quietly nodding at every slight delay only to get caught flat-footed when the rule gets junked entirely.

This story has been updated since it was first published.