A coalition of 22 statesincluding California and New York, six cities and the District of Columbia filed a lawsuit in the U.S. Court of Appeals in Washington this week in an attempt to block repeal and replace of the Clean Power Plan, an Obama-era policy that set emission-reduction targets, required states to restrict their use of coal-burning power plants and mandated a switch to renewable energy.

California Attorney General Xavier Becerra, Gov. Gavin Newsom, and California Air Resources Board Chair Mary Nichols announced the move Tuesday, marking the state's latest battle in court over climate change.

In June, the Trump administration finalized its Affordable Clean Energy Rule, which replaces the Clean Power Plan with one that weakens the emissions targets and protects the coal industry. Environmental Protection Agency Administrator Andrew Wheeler said at the time that the administration’s new plan was constructed to protect low- and middle-income Americans from rising energy costs.

But California officials say the new rules will hurt both the climate and the economy.

“President Trump’s attempt to gut our nation’s Clean Power Plan is foolish — and it’s also unlawful,” Becerra said, arguing that Trump’s new plan is also bad for the emerging new energy market, expected to grow the economy. The CPP was also promised as a way to combat the rising costs of climate change, that would save the country up to $20 billion. “Because we’re prepared to confront the climate crisis head-on, we’re prepared to confront President Trump head-on in court.”

A Trump campaign promise

Critics have cast Trump’s plan as a coal bailout, and an effort to fulfill his campaign promises to prop up the dying industry.

The Clean Power Plan, passed in 2015, was produced in partnership with states and cities across the country amid calls for plans to curb power plant pollution — the second-highest source of greenhouse gas emissions. It was designed to reduce power plant emissions 32% below 2005 levels by 2030, to meet targets set at the U.N. Paris Agreement, which the U.S. pulled out of under President Trump.

Under the plan, 47 states were assigned specific emissions targets as part of the EPA’s regulatory jurisdiction, awarded in the Clean Air Act. At the time, analysts found that the move would prevent roughly 3,600 pollution-caused deaths a year, along with 90,000 child asthma attacks and 1,700 heart attacks.

It was never implemented.

In 2016, 27 states joined by pro-coal business groups sued the Obama administration to block the CPP, a lawsuit that resulted in an issued stay from the Supreme Court and bought enough time for Trump to begin repealing it after he was elected.

Arguing that the ACE rule now constricts the Environmental Protection Agency’s regulatory responsibilities under the Clean Air Act, California, New York and the other jurisdictions that filed suit this week asserted in their lawsuit that Trump’s plan would not reduce greenhouse gas emissions from power plants, putting both the environment and human health at risk.

"They are in the short-term business," Newsom said of the Trump administration. "California is in the future business. We are leaping ahead," he added, saying the world is looking to the state to take on Trump and defend climate policies.

California vs. Trump

California has been active in challenging the president over the last three years, filing more than two dozen lawsuits against the administration's new policies. This week, Becerra also issued a statement challenging administration's rollbacks of the Endangered Species Act.

During Tuesday's news conference, Newsom said witha smile that recent changes put forth by the Trump administration had made him miss Richard Nixon. Nixon, a Republican, was the president who signed the Endangered Species Act in 1973.

Newsom argued that California was also leading by example. The Democratic governor said California's investment into renewable energies is expanding the state's economy much faster than the nation's growth. According to the state Department of Finance, California's economy grew at 3.6% in 2017, compared to 2.2% for the nation as a whole.

"Eat your heart out Donald Trump," he said with a smile, adding that California was proving that climate-consciousness doesn't have to break the bank.

News of the lawsuit came on the heels of updates on California’s progress toward its own plans to cut greenhouse gas emissions and the economic growth generated by the efforts. Newsom’s office said Monday that the state is ahead of schedule and that for the first time more energy in the state's power grid had been generated by renewable sources, like solar and wind,while fossil fuels were in the minority.

“California is proving that smart climate policies are good for our economy and good for the planet,” Newsom said in a statement Monday. “As the Trump administration attempts to obliterate national climate protections, California will continue advancing the cause of American climate leadership.”