The Obama administration on Monday will propose new environmental rules that seek to cut emissions from U.S. power plants by 30 percent from 2005 levels by 2030, according to news reports on Sunday.
Aiming to bypass a divided Congress by issuing regulation through the Environmental Protection Agency (EPA), the anticipated Monday announcement is U.S. President Barack Obama's boldest action yet to address climate change.
If successful, the proposal would lead to the first-ever rules aimed at carbon emissions from existing power plants.
States would have broad latitude in terms of how to meet a carbon standard, according to The New York Times and The Wall Street Journal, which first reported the preview of the rule on Sunday.
Options could include joining or starting a cap and trade program, which sets limits on emissions and then allows for the purchase and sale of pollution permits; boosting the share of renewable energy in electricity generation; and tightening efficiency standards.
The proposed rules come nearly a month after a sweeping national climate assessment that catalogued a range of impacts already occurring as a result of climate change.
Reducing greenhouse gases is a key way to address climate change, but it also has implications for public health, a point Obama stressed in his weekly address Saturday promoting the pending standard. (See related story: "One Key Question on Obama's Push Against Climate Change: Will It Matter?")
"In America, we don't have to choose between the health of our economy and the health of our children," the president said, anticipating critics from the coal industry and elsewhere who have said that tightening power plant standards would kill jobs and hurt the economy. (See related story: "Ahead of Proposed U.S. Power Plant Rules, the Spin Scramble Begins.")
"As President, and as a parent, I refuse to condemn our children to a planet that's beyond fixing," Obama said, acknowledging "tough choices" on the way to a cleaner economy. "But a low-carbon, clean energy economy can be an engine of growth for decades to come. America will build that engine." (See related story: "Federal Climate Change Report Highlights Risks for Americans.")
The 30 percent target Monday is slightly higher than earlier reports that predicted Obama would seek a 25 percent overall cut in emissions from the nation's existing power plants, which are responsible for about 40 percent of the carbon pollution.
But in setting the baseline year at 2005, the Obama administration allows states to count emissions reductions that have already been happening thanks in part to a nationwide shift to cleaner-burning natural gas.
The 30-percent target is also for 2030, rather than 2020, as some had predicted, allowing more time for the reduction.
Overall, greenhouse gas emissions in the United States already dropped nearly 12 percent between 2005 and 2012, and some states have renewable energy targets and efficiency-boosting measures in place that put them in a good position to meet the EPA's target.
In an analysis last week of ten states, including coal-reliant Pennsylvania and Ohio, the environmental research organization World Resources Institute (WRI) predicted that all those states would be able to achieve "moderate to ambitious" reductions in their emissions.
EPA Administrator Gina McCarthy is expected to announce more details about the proposed rules Monday. After that, the agency will consider public comment and work to finalize the rule within a one-year period. Obama has asked the EPA to finalize the rule by June 2015, and states would have a year from that point to create and submit their implementation plans.
"This momentous development raises the bar for controlling carbon emissions in the United States," World Resources Institute president Andrew Steer said in a statement released Sunday. "It's the most important action available to cut US emissions—and the Obama administration has seized the opportunity." (Take the quiz: "What You Don't Know About Climate Change Science.")
This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.