The states' lawsuit was aimed originally at coal-fired power plants.

The silence is deafening since the US Supreme Court ruled this week that states can’t take utilities to court over greenhouse gas (GHG) emissions on their own.

NPR’s reporting of the decision calls it “the court’s most important environmental ruling in years.”

But here in California, I’m seeing mainly tepid reaction from officials — and without the usual cavalcade of releases from industry and environmental groups, applauding or condemning. In response to an email inquiry I made after the ruling came out, Mary Nichols, chair of the California Air Resources Board, replied that the ruling:

“…re-affirms that EPA has the authority and responsibility to regulate greenhouse gas pollution in order to protect the public health and welfare from the urgent threat of climate change. The careful, deliberate approaches developed under the Clean Air Act – including California’s Clean Cars rule – provide a more reasonable and feasible alternative to the uncertainty of court-imposed limits on carbon pollution.”

California was one of six states involved in the case, which dates back to 2004. But that was before the EPA had taken definitive steps to assert its own regulation of greenhouse gases (a role upheld by the Supreme Court in 2007).

Air Board spokesman Stanley Young explained that California’s participation in the suit was “an effort by California to get some kind of national action on the climate front. Now that EPA is fully engaged, that kind of judicial action is no longer necessary.”

Just how “fully engaged” the Environmental Protection Agency is remains a matter of some debate. The federal agency recently postponed release of a draft rule on GHG emissions from power plants.

The full decision is available as a PDF download from the Supreme Court website.