When President Barack Obama took the oath of office last month, the dozens of new Members of Congress who braved the cold witnessed the historic swearing-in of a long-shot Democratic reformer, elected in part on a pledge to wean the United States off foreign oil.

For Rep. Ed Markey (D-Mass.), who was also in the crowd, it was a familiar scene.

In 1977, as a 30-year-old freshman lawmaker, Markey attended the inauguration of Jimmy Carter, the underdog former Georgia governor who promised a new national energy policy in the wake of the 1973 Arab oil embargo.

But the mix of renewable and conservation policies at the heart of Carter’s energy plan failed to survive the Reagan presidency. And as public outrage over the oil shocks of the 1970s diminished, so did the hopes of those people seeking a transformative energy strategy.

Thirty-two years later, the United States is once again on the cusp of an energy revolution, propelled not just by oil fatigue but also global warming.

This time around Markey — who at 62 has spent half his life in the House and ranks among its most senior Members — will play a leading role in seeing the new clean energy agenda to fruition.

He emerged last month from a shakeup of the powerful Energy and Commerce Committee holding the reins of the new Subcommittee on Energy and Environment, which will be the House’s starting point for sweeping climate legislation that Speaker Nancy Pelosi (D-Calif.) wants to pass before the year is out. The new role also gives Markey the legislative authority that the Energy Independence and Global Warming Committee, which he’s chaired since its creation in 2007, lacks.

While his newfound clout was unforeseen in the early days of George W. Bush’s presidency, when Republicans dominated Washington, D.C., Markey in a recent interview called it inevitable that energy would re-emerge as a top issue for Congress.

“I’m not surprised it’s come back,” he said in his Rayburn office, where a large solar panel salvaged from a Congressional exhibit has hung since the 1980s. “I am surprised it has taken this long.”

He’s anxious to get to work after what he calls the “lost years” of the Bush administration, which opposed regulating greenhouse gases. Making up for that lost time and getting a cap-and-trade scheme up and running has replaced the former president’s obstinacy as the chief obstacle for tackling global warming, he said.

“We’re behind the rest of the industrialized world in debating, thinking about and implementing these policies,” he said.

It has not been for a lack of effort on Markey’s part. He’s been an outspoken fixture in the environmental arena since the start of his Congressional career, shaping policy from his seats on the Energy and Commerce and Natural Resources committees.

He quickly established himself as a nuclear watchdog after winning his seat in 1976, and he was an early advocate for energy efficiency as chairman of the now-defunct Subcommittee on Energy Conservation and Power during the 1980s. Markey has been a passionate opponent of oil and gas drilling on public lands, and he spent a decade pushing for the increase in federal fuel-economy standards that was signed into law in 2007.

His oratory skills are legendary, though for one frequent legislative foe — Rep. Joe Barton (R-Texas), the ranking member on the Energy Committee — something of a running joke.

“I never thought I’d see the day when Congressman Markey would vote against allowing himself a chance to speak,” Barton deadpanned during the panel’s organizational meeting last month, after Markey sided with Democrats to defeat a proposal that would have guaranteed members the right to offer opening statements during hearings.

Environmental groups consider Markey among their closest allies on the Hill. “Ed Markey has been an absolute steadfast environmental champion,” said Anna Aurilio, the director of the Washington office for Environment America. “The top priorities of the environmental movement have been his top priorities.”

It’s Markey’s environmental credentials that concern industry lobbyists, who fear banishment as his subcommittee drafts sweeping energy legislation this spring.

Former Rep. Thomas Corcoran (R-Ill.), who was elected to the House the same year as Markey, said he rarely saw eye-to-eye with him when they served together on the Energy panel during the 1980s. “We duked it out on a few issues,” he recalled recently.

But he said he’s always held Markey in high regard for his intellect and sense of humor, a view shared by many Republicans ideologically at odds with the liberal Massachusetts Democrat.

Corcoran, who currently lobbies on behalf of unconventional fuels opposed by environmentalists, said he expects Markey to stay true to his green roots while at the helm of the Subcommittee on Energy. But he believes the Democrat will surprise some Republicans by allowing a fair airing and consideration of opposing viewpoints.

“I think his character and personality and his commitment to good government would encourage him to do that,” he said.

Aurilio said Markey has shown adeptness throughout his career at finding support among Republicans of all ideological stripes. “He’s always reached out to Republicans,” she said.

For example, last year Markey teamed up with Rep. Roscoe Bartlett (R-Md.) — a conservative who shares some of his energy views but who also supports nuclear power and expanded oil and gas drilling — to push into law language that requires a Defense Department review of national security risks from global warming.

Markey insists he can win GOP support for the cap-and-trade bill that will originate in his subcommittee. He points to his work on the landmark Telecommunications Act of 1996 — now framed and hanging on his office wall along with the signing pen used by President Bill Clinton — as proof of his ability to find bipartisan compromise. The bill passed the House 414-16.

“At the end of the day, it was a bill endorsed not only by the industries that were being regulated but by all the consumer groups as well,” he said of the negotiations he conducted as the chairman of the Subcommittee on Telecommunications, a role he recently traded with Rep. Rick Boucher (D-Va.) to focus on global warming.

Just as the telecommunications bill paved the way for broadband, Markey says the climate change bill will unleash a torrent of innovation and new energy technologies. “This is now an equivalent revolution ready to go,” he said.

And unlike Carter’s efforts, Markey says the looming energy transformation won’t easily be undone by shifting political winds.

“This second energy shock, which matches anything that happened in the 1970s, guarantees the revolution will take place,” he said. “I don’t think any future administration can without great peril, derail what is about to unfold in the next several years.”