On Monday afternoon, Michael Bloomberg, the billionaire businessman and former three-term Mayor of New York City, escaped to a deserted ballroom at the Grand Hyatt, in midtown Manhattan, to talk about climate change. Moments earlier, he had announced to attendees of the Bloomberg New Energy Finance summit that his philanthropic organization was partnering with the Canadian and British governments to expedite the global eradication of coal mining. His two new partners—Catherine McKenna, Canada’s minister of environment and climate change, and Claire Perry, the United Kingdom’s minister of state for energy and clean growth—came along for the discussion.

As the only person not representing a country, Bloomberg, in his new role as the U.N.’s special envoy for climate action, seemed like a substitute for American leadership—an alternative to the climate-denying Trump Administration, which Bloomberg called “a meshuggener.” But he immediately brushed aside the idea that the federal government, in this country, at least, can have a major impact on fuel sources or climate policy. “Coal will go away in any place where there’s a free market, for sure, because the market just forces that, the economics force it,” he told me. “O.K., the federal government can change some environmental regulations, but companies are going to put in the environmental safeguards anyway. Their stockholders are insisting on it, their employees are insisting on it, their customers are insisting on it, and, at the state level, they’re insisting on it.” Of greater concern, he said, are countries in which “the government has set the price for coal or whatever and is subsidizing it.” Last fall, McKenna and Perry founded the Powering Past Coal Alliance, which aims, in part, to help these countries adopt cleaner fuels. Sixty nations, states, cities, and companies have so far joined its polyglot roster.

At a few points during the conversation, Bloomberg returned to the idea that future targets for eliminating coal plants—2030 for developed countries; 2040 for China; 2050 for the rest of the world—don’t resonate with the public. “Twenty-anything sounds a long ways away, and so people don’t get their heads around it,” he said. “If you want people to sign on to an environmental issue, convince them that it is not climate change, it’s the environment. You say, ‘It’s your kid who’s going to go to the hospital with an asthma attack.’ ” Bloomberg drew an analogy with another of his causes, the fight against tobacco. “If you smoke—and you’ve got to be really stupid to smoke—then Darwin is at work,” he said. “The trouble with this stuff, what we’re talking about here, is you can do stupid things that hurt everybody for a long time.” McKenna noted that, in Ontario, once coal power was entirely eliminated, the province went from having fifty smog days a year to none.

One of the summit’s speakers, earlier in the day, was Rick Perry, the Secretary of Energy, who is an unashamed supporter of the coal industry. (Last week, a former D.O.E. employee petitioned for whistle-blower status, alleging “evidence of criminal corruption, obstruction of justice, and ethics violations” related to Perry’s relationship with the coal tycoon Robert Murray.) In his remarks, Perry said that his department was currently examining an emergency request from FirstEnergy Solutions, one of the largest electric utilities in the country, for help saving its struggling nuclear and coal plants. The company recently filed for Chapter 11 bankruptcy protection, and was asking Perry to invoke an obscure provision of the Federal Power Act that would keep its plants online by guaranteeing their profits. (One of the company’s D.C. lobbyists, Jeff Miller, was the campaign manager for Perry’s 2016 Presidential run.) Critics such as Nora Mead Brownell, who served on the Federal Energy Regulatory Commission under George W. Bush, have argued that granting FirstEnergy’s request would be a heavy-handed intervention in a competitive power market. Brownell called the request a “real tragedy.”

“It does not help that our federal government is opposed to some rational things and is putting out some of the drivel that they do,” Bloomberg said. “But I would say that President Trump has been phenomenally helpful in galvanizing the pro-environmental people.” To date, Bloomberg Philanthropies has spent a hundred and twenty-five million dollars on its anti-coal campaigns, funnelling much of the money to the Sierra Club’s Beyond Coal initiative, which targets communities where coal plants are located. (Some has also gone to job-training charities in coal country, to support out-of-work miners.) Since Bloomberg first became active on the issue, in 2011, fifty per cent of this country’s coal plants have been retired. His hope, he said, is to see just a handful of coal plants left in the United States in a few years. The next thing to worry about, he continued, is the shipping industry. “They use this terrible bunker oil,” he said. He could start by addressing his own foundation’s investments: Bloomberg Philanthropies has divested its portfolios from coal but not from oil or gas.

On Tuesday, however, Perry’s old friend and campaign supporter Robert Murray, the founder and C.E.O. of Murray Energy, the biggest private coal company in the country, addressed the summit. “I’m probably the only coal guy in this room,” he said. Murray owns a large number of the domestic mines that sell coal to FirstEnergy, and he was there to make the case that coal is the only reliable fuel source that this country has—especially during extreme weather events such as this winter’s bomb cyclone. It was his opinion that the federal government must intervene. “It’s probably the only option right now,” he said. “We have the responsibility to make sure grandma doesn’t die on the operating table.” Perry, in his speech, had been more circumspect about FirstEnergy’s request. “It’s not the only way,” he said. McKenna, for her part, believes that the reliability question is a canard. “There’s this idea that you need to have coal for stability of the grid, and that’s just not true,” she said. In Canada, she noted, eighty per cent of energy is clean, meaning that the nation’s electric grid is mostly not backstopped by coal.

Murray Energy holds about three billion dollars in coal reserves. Bloomberg is worth fifty billion. Whom will the Trump Administration heed?