The controversial outlines – which were first promised in Obama’s June 25 CAP announcement – are the first-ever national limits for pollution from future coal-fired plants. They limit new facilities of 25 megawatts or more to a maximum of 1100 pounds per megawatt of electricity produced.

The standards are formally known as “Power Sector Carbon Pollution Standards”, as noted by agency administrator Gina McCarthy. They will put a block on any new plants without CO2 capture, including advanced technology such as steam-electric coal complexes.

The EPA did note that plants would have the option to meet a somewhat tighter limit if they choose to average emissions over multiple years, which officials said would give units additional operational flexibility.

The rules also impose inaugural CO2 limits on combined-cycle natural gas plants of 1000lbs (454 kilograms) per megawatt hour, though many say the mandate will be easier to meet when many of those types of facilities already average about 800lb/MWh.

McCarthy said the proposal, from the perspective of both coal and gas, would “pave the way for the new generation of power plants in this country” as part of the EPA’s larger plan to slow climate change, which she said was “one of the most significant public health challenges of our time”

“By taking commonsense action to limit carbon pollution from new power plants, we can slow the effects of climate change and fulfill our obligation to ensure a safe and healthy environment for our children,” she said.

“These standards will also spark the innovation we need to build the next generation of power plants, helping grow a more sustainable clean energy economy.”

McCarthy spoke to the new outlines during a National Press Club event Friday where she said the agency was confident the standards would be “flexible and achievable” for the sector.

“Power plans are the single largest source of carbon pollution,” she said.

However, McCarthy noted that the agency wanted to keep from damaging the coal industry by rolling out mandates that would help allow adaptation and encourage the development of carbon dioxide reduction technologies.

“This proposal, rather than killing future coal, actually sets up a certain pathway forward for coal to continue to be part of the diverse mix in this country,” she said in her speech.

“We know that coal is going to be part of the energy generation that we rely on substantially over the next few decades.

“Why wouldn’t we now acknowledge and invest in the kind of technologies that will allow coal a future long beyond that?”

Quick to applaud the administration’s proposal was the Sierra Club, which said the outlines proved the administration was serious about fighting “climate disruption”, and that the move was supported by its 2.1 million members.

“Big polluters have been getting a free ride for decades, while Americans foot the bill in the form of asthma attacks, respiratory illness, floods, wildfires and superstorms,” Sierra Club executive director Michael Brune said.

“We look forward to strong final standards for both coal and gas plants, as well as a strong proposal for EPA’s upcoming carbon pollution protections for existing power plants [due next year].”

One of the first US producers to react to the announcement was Consol Energy, which called the proposal “a dangerous and unnecessary action at a time when the US continues to sluggishly inch toward economic recovery”.

“The President is legislating through regulatory bodies on an issue where Congress and the American people have repeatedly rejected his chosen path,” the company said.

“Poll after poll shows that the public prioritises jobs, the economy and skyrocketing debt as the defining issues of our time, yet the administration continues to move in a direction that will have no measurable impact on the stated goal of reductions in global CO2 concentrations and will only exacerbate the issues where Americans are demanding leadership by threatening to put our most abundant and affordable domestic resource on the sidelines.”

The emissions curbing announcement had a quick and painful impact on coal stocks mid-day Friday. While the proposal and its specifics were no big surprise, coal stocks including Consol, Arch Coal, Alpha Natural Resources, Peabody Energy, Cloud Peak Energy were down anywhere from 0.6% to 4.6% mid-day.

Read tomorrow’s edition of ILN for a feature overview of many more reactions from across the coal mining community.