US states to sue Trump administration over freezing fuel efficiency requirements

Nineteen US states have announced plans to sue the Trump administration over its "reckless and illegal plan" to rollback Obama-era clean car rules.

The US government on Thursday proposed weakening fuel efficiency requirements for cars and trucks, referred to as the clean car rule. 

President Donald Trump's proposal also undercuts California's authority to set its own stricter emissions rules for the state.

The proposal freezes fuel efficiency requirements for America's cars and trucks until 2026 - repealing one of Washington's most significant steps in recent years to curb greenhouse gas.

Signalling what is likely to be the start of a protracted legal battle, some 19 states and Washington DC have announced they intend to sue to the administration over the move. 

"We are prepared to go to court to put the brakes on this reckless and illegal plan," said Massachusetts Attorney General Maura Healey, who is part of the multi-state lawsuit. 

The state coalition, led by California Attorney General Xavier Becerra, includes legal representatives from jurisdictions that have adopted California's more stringent vehicle emissions standards.

Officials under President Barack Obama argued requiring vehicles to be more efficient would improve the public's health, reduce climate change and save motorists money.

The measures - which were due to come into effect by 2025 - were seen as one of the most significant steps Washington has taken to curb climate-changing greenhouse gas emissions.

Thursday's proposal from the Transportation Department and Environmental Protection Agency (EPA), argued the tough standards "are no longer appropriate and reasonable" beyond 2020.

The requirements will be frozen at 2020 levels until 2026, and require dramatically fewer electric vehicles, the proposal said.

The Trump administration has argued the freeze will lower vehicle prices for consumers, but critics say it will cost consumers more at the pump and accelerate climate change.

The government estimates the policy will boost US oil consumption by about 500,000 barrels of oil a day by the 2030s. 

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Officials also argued it would prevent up to 1,000 traffic fatalities per year by reducing the price of new vehicles and so prompting people to buy newer, safer vehicles more quickly.

But according to Ms Healey, the expected rollback by the EPA would cost Americans as much as $236 billion on petrol, and add the carbon emissions equivalent of 400 million cars.

It would also put more lives at risk due to asthma-inducing emissions, she said.

The Transport Department and EPA are gauging public reaction and holding hearings before the rule changes. 

However the legal action is likely to delay any further developments in the near-future, the states that have adopted California's emission rules together make up about one third of the US auto market.

The proposal to roll back anti-pollution efforts is in line with President Donald Trump's decision last year to abandon the 2015 Paris Agreement, under which countries agreed to take steps to mitigate global warming.

California's Governor, Jerry Brown, said: "California will fight this stupidity in every conceivable way possible".

"For Trump to now destroy a law first enacted at the request of Ronald Reagan five decades ago is a betrayal and an assault on the health of Americans everywhere.

"Under his reckless scheme, motorists will pay more at the pump, get worse gas mileage and breathe dirtier air."