A series of rules and findings issued by the EPA are heralding the slow but steady arrival of economy-wide regulation of greenhouse gas emissions. Following the 2007 Supreme Court ruling in Massachusetts v. EPA, the agency has been compelled by scientific findings to protect the public health and welfare from global warming pollution under the Clean Air Act.

Big industries opposed to EPA action, charge that the application of existing law is an unjustified power grab, but last week their position met a signal defeat. A move by like-minded allies in the Senate to block the EPA by Congressional mandate failed. It was a closely watched vote. In the end, Senator Murkowski's resolution that would have curtailed the agency's action on greenhouse gases went down to defeat 47-53.

Now industry must look to a flurry of weak legal challenges to slow or stop a first wave of regulations on industrial sources of pollution that are slated to take effect in January 2011, a little more than six months away. They've filed a number of petitions challenging the EPA’s authority from several angles.

Earlier this month, the National Association of Manufacturers (NAM), led by former three-term Michigan Republican Governor John Engler, along with 19 other lobbying organizations, filed a petition in federal appeals court challenging the EPA’s interpretation of the “Johnson Memo.”

Written by Bush's EPA chief, the memo details when the EPA must regulate greenhouse gas emissions from stationary sources. The petitioners include the American Petroleum Institute, National Petrochemical and Refiners Association and the Western States Petroleum Association. A similar petition was filed in April by a coalition that includes the Industrial Minerals Association, Rosebud Mining Corporation and National Cattlemen’s Beef Association.

In a press release, NAM called the EPA regulation of greenhouse gas emissions “an overreach” and “power grab” by the agency. NAM is also a petitioner in a suit filed in February challenging the EPA’s endangerment finding on greenhouse gas emissions. Jeff Ostermayer, a NAM spokesperson, says that the organizations position is that “any changes to the Clean Air Act need to happen through Congress, not the EPA.”

Ostermayer would not comment on whether the organization would support Congressional climate legislation instead. I has opposed it up until this point. In 2009, Duke Energy publicly split from NAM over its position on climate issues. At the time, Duke Energy CEO Jim Rogers blamed the organizations refusal to address climate change for the rift.

A separate petition has been filed by the Southeastern Legal Foundation (SLF) along with a number of Republican members of Congress, challenging the endangerment finding. Calling the science on climate change “unsettled”, they are partnering with industry supported think tanks including the Cato Institute and Heritage Foundation.

In March, SLF filed a stay on the endangerment finding in the hopes of halting the forward progress of the EPA’s implementation of greenhouse gas standards for light-duty vehicles and pending regulation for stationary sources. SLF, founded by former Heritage Foundation chair Ben Blackburn, is a self-described “conservative public interest law firm.”

David Baron, Managing Attorney at Earthjustice, an environmental law firm representing the Environmental Defense Fund as an intervener in the challenges to the endangerment finding, says that most of the lawsuits are baseless and that this is no power grab, just the EPA following its mandate on the Clean Air Act.

“In the endangerment case, our position is that the science showing that greenhouse gas emissions form motor vehicles endanger public health and welfare is overwhelming,” says Baron. “There’s new evidence coming out all the time corroborating it. Once the EPA has properly found endangerment, it’s obligated under the law to set greenhouse gas limits on motor vehicle emissions, it doesn’t have discretion to do otherwise.”

Further, he explains, “once motor vehicle emissions are limited, the Clean Air Act unquestionably requires the EPA to limit emissions from large factories and power plants, the statutes require it.”

In April, the EPA asked the court to hold the challenge to the endangerment finding in abeyance until August 16 or until the EPA can respond to various petitions for reconsideration that were filed with the agency, whichever comes first. Despite a flurry of motions filed by states and petitioners on both sides of the issue, most observers expect the court to grant the abeyance.

The recent NAM complaint challenging the Johnson Memo is largely a legal placeholder. The organization has yet to file a statement of the legal basis for their challenge. They expect that the court will then set a schedule for motions, briefs and orgal arguments.