Climate change activists across America perked up Wednesday when President Biden, in an interview with the Weather Channel, claimed that he has “practically” already declared a national climate emergency.

The comments revived the dream of those activists that the president would declare a formal national emergency on the hotly debated issue, giving him sweeping powers to bypass Congress and force American industry to produce green technologies and curb the use and development of fossil fuels in the name of combating climate change.

Asked by the Weather Channel interviewer whether he intends to take such drastic action despite misgivings in Congress and the business community, Mr. Biden replied, “I’ve already done that.”

“We’ve conserved more land, we’ve rejoined the Paris Climate Accords, we’ve passed the $368 billion climate control facility. We’re moving. It is the existential threat to humanity.” When pressed as to whether he has actually declared a national emergency, the president replied, “Practically speaking, yes.”

Literally speaking, however, the president has not done that. He briefly contemplated it last summer after Congress stymied his efforts to embrace costly climate change initiatives. His allies in Congress and environmentalist circles urged him to do so after passage of the so-called Inflation Reduction Act, which was more about green energy than inflation, and have continued to do so ever since.

“The climate crisis is one of the biggest emergencies that our country has ever faced and time is running out,” a group of eight Democratic senators said in a letter to Mr. Biden at the time. “We need to build off the momentum from the IRA and make sure that we achieve the ambition this crisis requires, and what we have promised the world.  We urge you to act boldly, declare this crisis the national emergency that it is, and embark upon significant regulatory and administrative action.”

Mr. Biden’s supporters believe that declaring a national climate “emergency” would give the president unprecedented power to tackle climate change in ways that Congress has so far been unwilling to do. Mr. Biden used emergency declarations issued by his predecessor during the Covid pandemic, for example, to enforce lockdowns and mask compliance, impose vaccine mandates, and dramatically expand welfare spending without Congressional authorization.

Some in Congress and environmentalist circles believe a declaration of a climate emergency would allow Mr. Biden to tackle climate change as aggressively as he did Covid. He could, they say, halt crude oil exports, suspend operations on all offshore drilling leases, and halt private sector investment in foreign and domestic fossil fuel projects. He could also, they insist, use the Defense Production Act to force manufacturers to pivot to producing green energy technologies and use the Federal Emergency Management Agency to invest in clean energy projects.

The authority for such measures, they argue, rests in the 50-year-old National Emergencies Act, under which the president must formally declare an emergency in order to activate the special powers. Every president since Gerald Ford has signed at least one such emergency measure, mostly following natural disasters or to punish foreign adversaries. Mr. Biden has so far issued seven emergency declarations under the act, including one that halted Russian oil imports after its invasion of Ukraine.

Keenly aware of the possibility that Mr. Biden could bypass Congress on climate change issues, a group of Republican lawmakers in late June introduced legislation that would specifically prevent the president from doing just that. The so-called Real Emergencies Act would, according to one its sponsors, Senator Capito, “ensure the president cannot go further by declaring a national emergency, which would grant him more executive authority and grow the size of government all in the name of climate change.”

“The Biden administration has repeatedly governed by executive overreach when it comes to energy and environmental regulations, ignoring the law and doing so without congressional approval,” Ms. Capito said. “These regulations have made us less energy independent, led to higher prices for consumers, and created uncertainty for employers and workers across the country.”

A companion bill has been introduced in the House and could conceivably emerge from those chambers, but with Democrats likely to remain in control of the Senate through at least January of 2025, the measure is not likely to be passed by Congress. Even if it did, it would almost certainly be vetoed by the president. He still, in other words, has plenty of time to declare that emergency.