Following Sen. Joe Manchin III’s decision last week to walk away from clean energy legislation in the Senate, many Democrats have called on Mr. Biden to take executive action. As a result of this decision, Democrats and Mr. Biden are looking for other ways to achieve their goals on climate change.

In June, the Supreme Court limited the EPA’s authority to regulate climate-warming pollution from power plants, dealing a blow to another tool that Mr. Biden hoped to use.

Biden said he would use executive authority to rein in heat-trapping fossil fuels even after the two cornerstones of his climate plan had crashed and burned in Somerset, Mass.

Mr. Biden said climate change is an existential threat to our nation and the world. He made these remarks as sweltering heat disrupted transportation networks in the United Kingdom, melted factory roofs in China, and scored hed the South and West of the country. In response to Republican opposition to his climate proposals, Mr. Biden said, “This is an emergency, and I will treat it as such.”

The actions Mr. Biden announced on Wednesday will do little to help the United States reduce its carbon footprint significantly. As a result, the president’s actions primarily aim to reduce the impact of climate change on households and communities.

He announced the allocation of $2.3 billion from a Federal Emergency Management Agency program to help communities build structures and programs to withstand the intense heat, storms, fires, and floods that climate change has already brought.

Separately, he announced the expansion of the federal Low Income Home Energy Assistance Program, which helps people pay for winter heating. In addition to assisting people in cooling their homes in summer, the program will also be used to construct community cooling centers.

Following moves to expand wind development off the Atlantic and Pacific coasts in the past year, Mr. Biden directed the Interior Department to open the door to building offshore wind farms in the Gulf of Mexico.

On the way to the event, Gina McCarthy, the White House national climate adviser, explained that it was important for the president to understand the various work threads and lay them out in a way that is comfortable for him.

As Mr. Biden faces growing calls from his party to declare a national climate emergency, he can halt new federal oil drilling and ramp up wind, solar, and other clean energy projects. On Wednesday, a banner stating, “Declare National Climate Emergency,” welcomed Mr. Biden outside the Somerset facility.

Kerry, Mr. Biden’s climate envoy, said in an interview that Biden is “very close” to taking that step and that the debate within the administration is more about when the declaration should be made and how it should be implemented rather than whether it should be made.

“It is up to the president to decide when to do that,” Mr. Kerry said. Mr. Biden told reporters after the Massachusetts event that he had not yet declared the emergency because he was still “running the traps” with the authority that he did have, adding that he “will decide on that soon.”

Despite Biden’s hesitation on Wednesday, the White House repeatedly referred to climate change as an “emergency” in a fact sheet and the president’s remarks.

White House officials are still hesitant to declare a formal climate emergency because the actions it could unleash would almost certainly result in lawsuits from Republican states.

Given the nation’s tumultuous state, many in the Democratic base are frustrated by Mr. Biden’s slow implementation of climate regulations for power plants and automobiles. Despite the Supreme Court overturning Roe v. Wade and soaring inflation, Biden has urged Congress to act and Americans to vote, avoiding sweeping executive action that his administration fears could be challenged in court.

Several crises and inaction in Congress have put Mr. Biden in a bind just months before the midterm elections. Due to the possibility that Democrats could lose power over Republicans, legislation must be passed as soon as possible.

Data for Progress founder Sean McElwee said the hopes of an F.D.R.-type climate legacy had been replaced with a reversal of young women’s 50-year-old rights. It’s demoralizing, and maybe expectations were too high.”

Over the past year, Mr. Biden has directed the E.P.A. to create new regulations to cut emissions from the nation’s three most significant sources of planet-warming pollution: cars, power plants, and oil and gas wells. Experts said those rules substantially bite the nation’s carbon pollution, assuming they stand up to inevitable lawsuits from Republican states. But the rules are not expected to be completed until 2023 or 2024 — and their ambition could still be watered down in response to political objections from automakers, union workers, and swing state voters.

We will progress with these tools, but it won’t be as much as Biden hoped, said Jody Freeman, an environmental law professor at Harvard who advised the Obama White House on climate policy. “But making some progress is better than nothing – and over time, these rules could unlock new technologies and gains we can’t anticipate.”

The White House is still hoping Sen. Manchin will come back to the table in the fall to negotiate some portion of a climate change bill. Some Democrats see the slow pace and low profile of rule-making as a concession to Senator Manchin, a coal state senator who has opposed many E.P.A. rules.

“I don’t know what Congress or any senator anticipates right now,” McCarthy said. “But the president is acknowledging the challenge.”

If Congress does not act to cut greenhouse gases, Mr. Biden will not be able to reach his pledge to cut greenhouse gas emissions in half by the end of the decade. Scientists say the United States must reduce this much pollution to help prevent the planet from warming by 1.5 degrees Celsius over preindustrial times. That is the threshold past which scientists say we cannot avoid the most catastrophic impacts of a warming planet – deadly heat waves, widespread wildfires, devastating storms, floods, and droughts. Over that time, the earth has already warmed 1.1 degrees Celsius.

Young people are tired of receiving scraps from our government, said Varshini Prakash, executive director of the Sunrise Movement, an environmental group. “We’ve seen executive actions and the slow death of climate legislation in Congress.”

Moreover, Kerry emphasized the dire consequences of the United States’ inability to pass climate legislation.

There are fires in Europe, houses burning, runways melting, railroad trains that can’t run fast because the metal is melting,” Kerry said. Greenhouse gas emissions will not slow because people can’t get their act together.

On the international stage, Mr. Kerry said the struggle to enact Mr. Biden’s once-ambitious proposals is already causing concern.

Mr. Kerry said he was asked about the impact of the recent Supreme Court E.P.A. case by a Chinese negotiator in Berlin earlier this week for a climate conference. Others questioned whether Mr. Biden could fulfill his pledge to reduce U.S. emissions by roughly half.

It is exciting to hear people in other countries ask you if you can meet your goals,” Mr. Kerry commented, adding that he is concerned other countries might use Congress’ inaction as an excuse not to reduce emissions.

Climate change resistance also “undermines the narrative” among some critics that the United States is a declining nation, Mr. Kerry said.

He added that the argument is hard to counter when you don’t pass legislation.