California Gov. Jerry Brown blasted the Trump administration's proposal to rewrite Obama-era greenhouse gas rules in favor of coal-fired power plants as "a declaration of war against America and all of humanity."

On Tuesday, the U.S. Environmental Protection Agency proposed a new rule for greenhouse gas emissions from existing coal-fired electric utility generating units and power plants known as the Affordable Clean Energy Rule, which will give states more power to set their own emission standards at plants.

Trump's EPA criticized the Obama administration's Clean Power Plan as "overly prescriptive and burdensome," adding that the new rule it proposed "instead empowers states, promotes energy independence, and facilitates economic growth and job creation."

Brown almost immediately slammed the Trump administration's move.

"This is a declaration of war against America and all of humanity – it will not stand," Brown said in a statement. "Truth and common sense will triumph over Trump's insanity."

In the United States, power plants represent the second largest share of greenhouse gas emissions after the transportation sector. About two-thirds of the electricity generated at power plants comes burning fossil fuels, mostly coal or natural gas.

The announcement by the EPA had been widely expected ever since President Donald Trump signed an executive order in March 2017 to promote energy independence and promote coal. That executive order called on departments and agencies to review existing regulations "that unduly burden the development of domestic energy resources."

A release issued by the governor said the White House's new plan "encourages the use of coal – and undercuts the nation's commitment to clean energy."

Brown said the state has no plans to roll back its greenhouse gas emissions targets and will instead "exceed the targets" in the Obama-era Clean Power Plan. The Democratic governor has been a frequent critic of Trump's views on climate change and the environment.

Earlier this month, Brown criticized the Trump administration's plan to roll back the nation's clean car standards. "California will fight this stupidity in every conceivable way possible." Brown said at the time.

The White House didn't immediately respond to a request for comment on Brown's remarks.

In 2017, the Obama EPA contended that its Clean Power Plan would save annual emissions equal to more than 165 million cars, or about 70 percent of the nation's passenger vehicles.

According to the state, California is on track to produce one-third of its power from renewable energy sources by 2020 and expects to generate half of its energy from renewable sources by 2030.

California relies on coal for slightly more than 4 percent of its power mix, while nationally that figure stands at just over 30 percent, according to the U.S. Energy Information Administration. Renewable energy sources represented 29 percent of the state's power mix last year, with solar and wind accounting for the bulk of it.

Climate change legislation passed by the state two years ago commits California to reducing greenhouse gas emissions 40 percent below 1990 levels by 2030.

A key element of the state's program to cut greenhouse gas emissions is a cap-and-trade program, which includes a quarterly auction of carbon allowances. Since 2013, the auctions have raised about $8 billion in proceeds, including revenue to fund the state's high-speed rail project.