President Barack Obama on Tuesday imposed the first-ever order for utilities to clean up carbon emissions at existing power plants, a move expected to have a profound impact on Atlanta-based Southern Co. and its large number of coal-fired facilities.

The aggressive plan to combat climate change does not require Congressional approval and likely will take years to put in place. Republicans, the coal industry and utilities already have come out against the measure, saying it could drive up electricity prices for consumers and slow the nation’s economic recovery.

“This is a challenge that does not pause for partisan gridlock; it demands our attention now,” Obama said on the campus of Georgetown University, describing why he was bypassing Congress. “And this is my plan to meet it — a plan to cut carbon pollution; a plan to protect our country from the impacts of climate change; and a plan to lead the world in a coordinated assault on a changing climate.”

Southern did not give details on how the plan could impact its utilities, which include Georgia Power. A year ago, Georgia Power’s Plant Scherer and Bowen topped the Environmental Protection Agency’s list of carbon emitters, in part because the plants are some of the largest in the country.

Southern executives have repeatedly said any energy or climate regulation should be left to Congress.

“Congress is best equipped to develop a national energy policy that meets the needs of all sectors of our nation, striking an appropriate balance to protect the environment and ensure energy security,” the company said.

The president’s proposals include boosting the amount of renewable electricity being used on public land and in federally subsidized housing. Doing so would increase business for solar, wind and biomass companies, which have faced a challenging political and economic climate in the Southeast.

“(The president’s plan) highlights the need for Georgia’s leaders to take a practical and serious look at the policies holding the state back from the jobs and investment we could be creating with its enormous solar potential,” said Brion Fitzpatrick, vice chairman of the Georgia Solar Energy Association and director of business development at Inman Solar.

Curbing heat-trapping greenhouse gas emissions is the latest in a string of orders from the Obama administration to help clean up the environment. The others, which include reducing mercury and other air toxins that come from coal-fired plants, are forcing Georgia Power and other utilities to close dozens of coal- and oil-fired units or equip them with pollution controls.

The U.S. Supreme Court agreed Monday to review a challenge to another regulation, one that would limit power-plant emissions blowing across state lines. The rule, which requires cuts cuts in nitrogen oxide and sulfur dioxide emissions, could lead to additional power plant closures.

U.S. Rep. Tom Price, a Roswell Republican, predicted tougher carbon regulations “will only make fuel and electricity – as well as basic goods and services – more expensive for hardworking Americans.”

U.S. Rep. Hank Johnson, a DeKalb County Democrat, praised the plan and said that it’s appropriate to bypass Congress when it’s “mired in gridlock and unable to move on the important issues of the day, a clean environment being one of them.”

The president’s also called on the country to become more energy efficient. The administration said it will try to work with countries such as China and India — among the world’s top carbon emitters — to reduce pollution worldwide.

The proposals come at a time when Georgia utility regulators are reviewing Georgia Power’s long-term energy plan, which includes closing 15 coal- and oil-fired units. The utility is spending more than $5 billion to install pollution controls to curb sulfur dioxide, nitrogen oxide and mercury at its coal plants.

Separate from that, the utility pledged last year to boost the amount of solar it will distribute to its customers tenfold over the next few years. But its 20-year outlook doesn’t include adding more solar beyond that, angering clean energy and solar advocates.

Georgia Power says it does not need to add any more electricity, including renewable fuels, to its power grid because the utility has nearly twice the amount of excess capacity required by state regulations. Georgia Power also is building two nuclear reactors at Plant Vogtle in Waynesboro that are scheduled to open in 2017 and 2018. Obama mentioned the Vogtle project in his speech as a domestic energy success story.

Southern Co. has reduced the amount of electricity it gets from coal from 70 percent five years to roughly 35 percent today. The company’s Mississippi Power utility touts new technology to capture carbon emissions at its next-generation coal plant in Kemper County.

Yet, the energy giant ranks as the third-largest emitter of carbon dioxide in the United States, according to the Political Economy Research Institute at the University of Massachusetts, Amherst, using 2011 EPA data.

The president campaigned hard to increase renewable energy production and curb carbon emissions during his first term in office, but was unable to pass climate legislation even with Democratic majorities in Congress. The administration has been in a tug-of-war with environmental advocates, who think he’s not doing enough, as well as the energy industry, which says regulations are too restrictive.

One example of that tension is a letter signed by attorneys general in 21 states, including Georgia’s Sam Olens, saying they will sue the EPA if it agrees to settle on new greenhouse gas emissions standards without input from the states.