Vice President Kamala Harris pledged at a United Nations climate summit on Saturday that the United States would spend billions more to help developing nations fight and adapt to climate change, telling world leaders that “we must do more” to limit global temperature rise.
Her remarks followed an announcement by U.S. officials at the summit the same day that the federal government would, for the first time, require oil and gas producers to detect and fix leaks of methane.
It was the most ambitious move to reduce fossil fuel emissions that President Biden’s administration was expected to unveil at the summit, known as COP28. Methane is a potent greenhouse gas that wafts into the atmosphere from pipelines, drill sites and storage facilities, and dangerously speeds the rate of global warming.
Ms. Harris did not mention that new regulation in her remarks, which ran just under five minutes, and came before what was set to be an afternoon of sideline discussions with Middle Eastern leaders centered on the war between Israel and Hamas.
But the vice president, who was a late addition to the summit after Mr. Biden decided to skip it, highlighted what she said was nearly $1 trillion in new spending approved under the Biden administration for clean energy and climate efforts. She pushed for world leaders to go even further.
“We must have the ambition to meet this moment, to accelerate our investments and to lead with courage and conviction,” she said.
While many activists at the summit welcomed the methane announcement, they criticized the Biden administration for not doing more to end the burning of fossil fuels like coal, oil and gas. The United States has seen a surge in domestic oil production over the past year, and Mr. Biden has approved some new drilling leases that have drawn criticism from environmental groups.
“To keep global warming under internationally agreed limits, we need a fair, fast and funded phaseout of fossil fuels,” Lorne Stockman, a research director of the environmental group Oil Change International, said in a statement after the announcement. “So far, none of the methane actions announced by the U.S., the world’s largest oil and gas producer, meet the bar.”
Some groups at the summit also noted the fragility of Ms. Harris’s promise that the United States would send $3 billion to the Green Climate Fund, which benefits poorer nations. In the past, Republicans have blocked U.S. money for climate change work overseas, and the Biden administration has instead tapped discretionary funds within the State Department.
Mr. Biden has failed to persuade Congress to fulfill previous climate-assistance pledges. White House officials would not say on Saturday when or how the president would ask Congress to fund this new request, at a time when lawmakers are constrained by spending caps Mr. Biden negotiated with Republicans during a fight over the nation’s borrowing limit this year.
A formal Treasury Department announcement of the new pledge, which followed Ms. Harris’s remarks, noted that the $3 billion was “subject to the availability of funds.”
The methane rule, which was first announced at COP28 by Michael S. Regan, the administrator of the Environmental Protection Agency, came with more certainty: It is an administrative action that does not require the approval of Congress and is scheduled to take effect next year.
Methane is not as widely discussed as the carbon dioxide that results from burning fossil fuels, but it has become a rare area of progress this week at the global talks.
It is the second-most abundant greenhouse gas after carbon dioxide. Methane only lingers in the atmosphere about a decade after it is released, but it is about 80 times more powerful in the short term at trapping heat than carbon dioxide, which remains in the air for centuries.
Scientists say methane is responsible for more than a quarter of the warming that the planet has experienced since the preindustrial era. Cutting methane, they say, is essential to meeting the global goal of limiting warming to 1.5 degrees Celsius, a goal set in the Paris Agreement to avoid the worst effects of global warming, and acting now can help buy the planet time as nations grapple with the more contentious problem of slashing carbon dioxide emissions.
The new regulation would prevent 58 million tons of methane emissions by 2038, officials said. That’s about the equivalent of all the carbon dioxide emitted by American coal-fired power plants in a single year. Mr. Regan called it one of the most important policies the United States will have enacted to slow the rate of climate change over the next decade and a half.
“I’ve met face to face with generations of family members who have been impacted by this pollution for far too long,” Mr. Regan said at a news conference in Dubai, United Arab Emirates, where the summit was taking place. “This is historic news for our climate.”
Fred Krupp, the president of the Environmental Defense Fund, an advocacy group, called the policy “the most impactful climate rule that the United States has ever adopted in terms of addressing temperatures we would otherwise see.”
But Republicans in Congress said the regulation would hurt the gas industry and raise energy prices for Americans at home.
“Federal overreach to advance a misguided climate agenda has become a staple of the Biden administration,” Senator Shelley Moore Capito, Republican of West Virginia, said in a statement. She called the final rule “just one more example of these harmful regulations.”
For years, the fossil fuel industry has been divided over the methane regulations. Some large international companies, including BP, expressed support for the plan, while the Independent Petroleum Producers of America, which represents small and independent oil companies, said the rule could shut down 300,000 of the nation’s 750,000 low-production wells, which it called “essential to our country’s energy production.”
Climate activists said they hoped the new U.S. rule would pave the way for more global progress on curbing methane. For now, though, emissions are going in the wrong direction. Last year methane emissions rose, according to a report by the World Meteorological Organization.
Other commitments to reduce fossil fuel emissions were also made at the conference on Saturday. A coalition of 50 oil and gas companies — including ExxonMobil; Saudi Aramco; Adnoc, the state-owned oil company of the Emirates; ConocoPhillips and BP — pledged to reduce their methane emissions between 80 to 90 percent by the end of this decade.
The coalition, called the Global Decarbonization Accelerator, was the flagship announcement from the Emirates at COP28. It was denounced by 300 environmental groups, which said it did not go far enough to wind down fossil fuels.
The companies represent more than 40 percent of global oil production. The pledge is voluntary, but Bloomberg Philanthropies also announced a new $40 million program to bolster transparency in the ways companies measure and report leaks.
John Kerry, the U.S. special envoy for climate change, said that curbing methane leaks were the “easiest, quickest, cheapest, simplest” way to cut emissions, because the fixes essentially involve plugging leaks. “It’s mostly plumbing,” he said.
A separate coalition of countries, development banks and nonprofit organizations announced a new initiative to help developing nations phase out coal. The partnership, known as the Coal Transition Accelerator, will aim to provide affordable funding for poor countries seeking to build renewable power and repurpose coal infrastructure to support clean energy projects.
“The international community has a responsibility to support the emerging economies in their strategy to phase out coal,” Emmanuel Macron, the president of France, said in a meeting about the effort with the leaders of Vietnam, Malaysia and Indonesia. “We need to change the rules of the game if we want to accelerate.”
David Gelles contributed reporting.