As President Obama tries to fight global warming without any backing from a gridlocked Congress, he’s using every weapon in his executive arsenal. His Environmental Protection Agency will soon roll out controversial regulations on carbon pollution from coal-fired power plants. He’s told every Cabinet agency to look into ways it can use its authority to act on climate change. And now the administration is stocking the executive branch with an army of new appointees who have a history of working aggressively on climate issues and clean energy, often from leadership jobs at environmental advocacy groups.

It’s not surprising to see a president name a top nominee—for Cabinet secretary, say—who has led the way on an issue the White House cares about. In his first term, for example, Obama named as his Energy secretary Steven Chu, a Nobel physicist who had devoted his career to fighting climate change. With the executive branch the only avenue for the president to make an impact on climate policy, the Obama administration is filling out the second and third tiers of agencies—influential workhorse positions such as chiefs of staff, assistant secretaries, and heads of regulatory commissions—with appointees just as devoted to the cause, with the expectation that they’ll muscle through a climate and clean-energy agenda wherever they can.

The strategy is drawing cheers from environmentalists and fire from conservatives, who both agree that these behind-the-scenes positions have a sizable impact on shaping policy. “The president has made it … clear that he wants further action on climate to be a big part of his legacy,” said Frank O’Donnell, president of Clean Air Watch. “He’s not going to get cooperation from Congress, so the only way to carve out a legacy on climate is to have folks at federal agencies that can make things happen. Some of these jobs which no one’s ever heard of are being filled by people who can make things happen.”

Scott Segal, who lobbies for coal companies with the law firm Bracewell & Giuliani, wrote in an e-mail to National Journal, “Energy- and environmental-policy development has always been more about workhorses than show horses. The subject matter is arcane, and therefore the role of the less visible executive appointment in executive agencies looms large as complicated issues like carbon policy loom on the near-term event horizon.” Segal added, “For certain of these roles, the administration has shown a troubling predisposition to nominate individuals from the activist community…. What is needed are realistic and dispassionate professionals that can balance economic and environmental objectives with respect for the rule of law.”

Segal and others in industry are particularly incensed at Obama’s nomination of Ron Binz to chair the Federal Energy Regulatory Commission, a relatively obscure panel that nonetheless wields significant regulatory muscle in implementing energy policy. Binz, a former chairman of the Colorado Public Utilities Commission, drew outrage from the coal industry for helping to write a state law aimed at shutting down coal-fired power plants. In statements and speeches, he’s been up front about his philosophy of energy: He backs renewables over fossil fuels. His personal website has a “Philosophy” listing a series of talks and statements championing renewable energy. In an editorial slamming Binz as “radical,” The Wall Street Journal called him “the most important nominee you’ve never heard of.” As the drumbeat of opposition to Binz has increased, a group of environmental activists hired a Washington PR firm, VennSquared Communications, to campaign for him as he heads into what looks like a tough and testy Senate confirmation process. (Binz declined a request for an interview with National Journal, saying he intends to refrain from speaking to the press until after his Senate confirmation.)

Also raising eyebrows among conservatives is Obama’s July appointment of Kevin Knobloch, former president of the Union of Concerned Scientists and a longtime player in the world of climate policy and advocacy, as the Energy Department’s new chief of staff. “I cannot imagine a moment in history when we have had a window where the Department of Energy’s mission has been more important,” Knobloch said of the department’s plans to toughen energy-efficiency standards and innovate ways to burn fossil fuels more cleanly.

“Someone like Kevin Knobloch—an appointment like that would have been less likely in the first term,” said Paul Bledsoe, a senior climate-policy adviser in the Clinton White House. “The chief of staff to the Energy Department, Interior, EPA—those are important jobs. Those are people with a great deal of influence.” O’Donnell, president of Clean Air Watch, said, “I can’t imagine why Kevin would take that job unless he had a chance to do something big—something historic.”

Meanwhile, earlier this month, the Senate confirmed Dennis McGinn as assistant Navy secretary for energy installations and the environment. Although the position is little known, the appointment of McGinn, a retired Navy vice admiral who headed the American Council on Renewable Energy, signals Obama’s intent to keep using the Pentagon to drive renewable-energy technology. McGinn has served as cochairman of the CNA Military Advisory Board, which authored a prominent paper urging the defense community to prioritize climate change as a national security issue. He also has served as a fellow at the Rocky Mountain Institute, a think tank that publishes papers advocating policies to fight climate change and promote renewable energy.

“The appointment of Denny means this is not just a one-and-done issue,” said Douglas Wilson, a former assistant secretary of public affairs for the Pentagon. “What we’re seeing in these appointments is an effort not to have placeholders but people who have history in clean energy.”