Stung by the failure to secure a Senate vote on climate and energy legislation, leaders of some of the most influential green groups in the US are shifting efforts to defend the Environmental Protection Agency’s authority to write climate rules.

Groups like Environment America, the Sierra Club and the Union of Concerned Scientists, with more than 2.5 million members combined, have gone on the defensive. “The era of the big bill I think is over,” an environmentalist whose group has not yet come out publicly on the issue told the Capitol Hill news source Politico.

Politico reports that such groups are hoping to defend and expand on state and regional climate laws and compacts, including a carbon market for power plants operating in the Northeast and emerging systems in the West. And they will work at the state public utility commission level to make carbon dioxide emissions a crux in reviewing permits for new and existing coal-fired power plants.

The Sierra Club is spending $18 million and has 100 people across the country working on challenges to coal-fired electricity, Michael Brune, the group’s executive director, told Politico. He hopes to increase the budget to $25 million next year.

“We don’t think we can fight climate change without getting a comprehensive, economy-wide cap,” Brune told Politico. “At the same time, we think in the short term, more significant gains can be achieved by focusing on other strategies.”