US President Joe Biden speaks during the National Thanksgiving Turkey Pardoning Ceremony at the White House in Washington, DC Nov 19, 2021.Photo:Xinhua

US President Joe Biden is raising mileage standards for cars and trucks sold in the US in a bid to limit emissions, as the spending bill he counted on to fund the fight against climate change appears to be on life support.

The new regulations announced by the Environmental Protection Agency (EPA) on Monday reverse laxer standards passed under former president Donald Trump governing how far an automaker's cars must be able to travel on a gallon of gasoline, and show how Biden's White House is using regulatory power to curb emissions. 

The announcement comes as the president's Build Back Better (BBB) social spending plan may have suffered a mortal blow after a crucial Democratic senator said he would not support the $1.75 trillion proposal.

"We followed the science, we listened to stakeholders and we are setting robust and rigorous standards that will aggressively reduce the pollution that is harming people and our planet - and save families money at the same time," EPA Administrator Michael Regan said.

Under the new EPA rules, the average fleetwide fuel consumption standards would be phased in over three years from 2023 and rise to 55 miles (88.5 kilometers) per gallon by 2026.

That is up from 43 miles per gallon under regulations enacted in 2020, and the EPA estimates the new standards will save Americans between $210 and $420 billion on fuel costs by 2050. 

US automakers have already announced major investments in electric vehicles and more fuel-efficient cars, but industry group the Alliance for Automotive Innovation warned the new standards will be hard to meet without help from the government.

The "EPA's final rule for greenhouse gas emissions is even more aggressive than originally proposed, requiring a substantial increase in electric vehicle sales, well above the 4 percent of all light-duty sales today," its president John Bozzella said.

"Achieving the goals of this final rule will undoubtedly require enactment of supportive governmental policies - including consumer incentives, substantial infrastructure growth, fleet requirements and support for US manufacturing and supply chain development."

In contrast with Trump, Biden has made fighting climate change a priority for his administration, and was counting on BBB's passage to pay for expansive programs aimed at doing that.

But Democratic Senator Joe Manchin announced Sunday he would not vote for the bill, imperiling its passage in a Senate where Biden needs the vote of every Democrat to get legislation past Republican objections.

Emissions standards are one of Washington's most direct ways to act against pollution.

The transportation sector is the biggest source of carbon emissions in the country, and the EPA said the new regulations would remove more than 3 billion tons of greenhouse gas by 2050.

AFP