“It was so harrowing,” Mr. Deese recalled of the grim months of recession in the earliest days of President Obama’s first term, when as a 31-year-old Yale Law School student he played a central role on the White House team that executed an $85 billion government bailout of Chrysler and General Motors.
These days the crisis atmosphere is gone and unemployment is at 5.5 percent, but Mr. Deese is still running the economic numbers at the White House on a different kind of crisis that is preoccupying the president. Mr. Deese’s job as Mr. Obama’s senior adviser in charge of climate policy is to push the president’s ambitious environmental agenda to governors, industry executives and international negotiators — while under daily political attacks from Congress and the coal industry.
“It’s not the harrowing urgency of the economy falling off the cliff,” Mr. Deese, 37, said of his new job during a recent interview in his West Wing office, just steps down the hall from Mr. Obama’s. “But it’s the urgency of, ‘We have a limited amount of time left to change the trajectory on a really urgent crisis.’ ”
Last week Mr. Deese unveiled the heart of Mr. Obama’s agenda: a blueprint for cutting greenhouse gas pollution in the United States up to 28 percent over the next decade. The proposal, which is centered on Environmental Protection Agency regulations meant to drastically reduce planet-warming carbon dioxide emissions from the nation’s cars and coal-fired power plants, is the White House’s formal submission to the United Nations ahead of a global warming summit meeting in Paris in December.
Mr. Deese, who has a stuffed snowy owl on a shelf in his office and a sparse beard that gives him the look of a Vermont hipster, is in some ways an unlikely person to lead the effort. He has never held a job in environmental policy, has never participated in an international negotiations and has nothing approaching the years of knowledge of John D. Podesta, who ran the president’s climate change agenda until he stepped down in January as counselor to Mr. Obama.
But Mr. Deese, who must now make sales pitches to governors and participate in global talks, has a reputation as a fast study.
“With no business experience at all, he plunged into the auto thing with us and really figured it out,” said Steven Rattner, the financial adviser who led Mr. Obama’s auto bailout team. “He added an unbelievable amount of value with the way he thinks things through. I could totally trust his judgment.”
Instead of making the case for fighting global warming in the language of an environmental activist, Mr. Deese argues from the perspective of an economist, just as he did during the darkest days of the recession.
He loves to cite his favorite new statistic: a recent report by the International Energy Agency that found that last year, global gross domestic product grew 3 percent, while carbon dioxide emissions flatlined. Historically, economic growth has paralleled the growth in fossil fuel emissions.
“The data show it’s possible to grow the economy without growing pollution,” Mr. Deese said with visible excitement.
Known for pacing while he talks on the telephone and sometimes going without shoes in the office, Mr. Deese appears at his most animated when plunging headlong into the wonkery of an issue.
“This is somebody whose greatest joy is that swift arc up the learning curve,” said Gene Sperling, the president’s former national economics adviser. “He has both this amazing policy I.Q. that he can bring to any issue as well as the humility to reach out and find and listen to every expert on the planet on that issue.”
Mr. Deese is now on a very steep learning curve. In January, he flew to New Delhi with the president and was in the room as Mr. Obama urged Prime Minister Narendra Modi of India to cut his nation’s greenhouse gas emissions.
In March, Mr. Deese was in Kentucky, where anger against Mr. Obama’s climate change plan runs deep. The plan requires states to cut carbon emissions, effectively forcing them to change their energy supply from fossil fuels to renewable sources — a tough sell in a coal-mining state like Kentucky. There Mr. Deese appeared with Governor Steven L. Beshear, a Democrat, at an event promoting a federal program to help coal communities and then spoke with him for an hour afterward about the climate change plan.
But Mr. Deese has hardly assuaged the anger over the plan, particularly among Republicans who see it as either a war on coal or a vast overreach through the E.P.A. regulations of Mr. Obama’s executive authority. If put in place over the next year, the plan could drive major changes in the nation’s economy in the next decade, from shutting down coal-fired power plants, spurring renewable electricity generation and forcing automakers to build fleets of all-electric vehicles.
Senior staff members in the offices of Senator Mitch McConnell of Kentucky, the majority leader, and House Speaker John A. Boehner of Ohio said they have never heard from Mr. Deese.
“Apparently, he’s only talked to the press,” Donald Stewart, Mr. McConnell’s spokesman, said in an email.
Raised in Belmont, Mass., a Boston suburb, Mr. Deese grew up hiking, sailing and fishing in a home where the environment was important. (His mother is an engineer who works in renewable energy, and his father is a political science professor at Boston College.) He graduated in 2000 from Middlebury College in Vermont, went to Washington to work in international aid and was soon hired as a policy analyst by Mr. Sperling, who was then at the Center for American Progress, a liberal research organization.
Mr. Deese left Washington briefly to pursue his law degree but could not resist the lure of the 2008 presidential campaign, signing on as an economic policy adviser to Hillary Rodham Clinton and, after she conceded, switching over to Mr. Obama’s staff, where he has remained ever since. He completed his law degree in 2009, by mail from Washington.
Mr. Deese, who has a young daughter, arrives in the West Wing at 6:45 a.m. after a two-mile run to work, showers, then slings his yellow backpack on the hook on the back of his office door. He knows he does not have much time: The president and his allies fear that if the climate plan is not locked in place before Mr. Obama leaves office, a Republican president could undo it.
“You have to work fast — each day matters,” said Carol Browner, who served as Mr. Obama’s senior climate change adviser in his first term. “You have to ask, ‘Have we lost a day? Have we lost a week?’ ” As Mr. Deese put it, “It’s a different kind of emergency.”