Attorneys for the Pennsylvania Department of Environmental Protection urged a state court on Wednesday to toss out a case in its early stages that is seeking to dismantle a state climate rule by alleging it will not be effective enough.

The Commonwealth Court of Pennsylvania heard arguments in Pittsburgh on DEP’s preliminary objections to the challenge brought by owners of natural gas power plants.

In many ways, the case mirrors a pending challenge to the carbon-cutting rule that has already been argued at the court by state Republican legislators and coal-aligned interests.

The 2022 rule to join the Regional Greenhouse Gas Initiative, or RGGI, is designed to cut annual power sector greenhouse gas pollution in Pennsylvania by 26% by 2030. It requires fossil fuel power plants to pay for each ton of carbon dioxide they release.

A Commonwealth Court judge issued an injunction that put the rule on hold last July.

Challengers argue environmental regulators did not have the power to adopt the rule or join the multistate cooperative, and the hundreds of millions of dollars in projected annual revenue for clean air programs amounts to an unauthorized tax.

But the new case also brings a new argument: that DEP’s calculations for the beneficial impact of the rule are wrong and the rule will end up causing more climate harm than good.

The companies — Calpine Corp., Tenaska Westmoreland Management and Fairless Energy — own natural gas power plants in southwestern and eastern Pennsylvania.

They argue the rule will force their plants to run less, while some dirtier out-of-state power plants that do not have to pay for their pollution will run more, ultimately causing an increase in carbon dioxide emissions across the electric grid that covers the eastern half of the United States.

Attorneys representing DEP argued Wednesday that the companies have not supported that allegation with evidence, did not bring it up as part of the yearslong rule-making process and are barred from trying to undermine the state’s rationale for the rule at this stage.

“A party doesn’t get to say the agencies, when they were projecting future events, didn’t get it exactly right and so therefore the whole thing is unreasonable,” attorney Thomas Hazlett said.

Some judges on the seven-judge panel indicated they weren’t willing to dismiss the challenge so quickly.

“It is a pretty early stage,” Judge Anne Covey said. If the preliminary objections are granted, “we never get down the road any further to actually test what your argument is.”

Andrew Bockis, an attorney for the power plants, said the case should be allowed to continue and the companies look forward to supporting their claims with expert testimony.

Judge Michael Wojcik said the plants’ challenge seemed to repeat much that the court is already considering from the earlier cases brought by Republican legislators and coal groups.

“It’s like Groundhog Day again,” he said.

The Commonwealth Court heard arguments in those cases in November and has yet to issue a decision.

Laura writes about energy and more for the Pittsburgh Post-Gazette, but she's currently on strike.

Laura Legere

Laura writes about energy and more for the Pittsburgh Post-Gazette, but she's currently on strike.