President Obama announced rules Monday that he said would "end the limitless dumping of carbon pollution from power plants," a move that the White House says will slow climate change and transform the electricity grid if it withstands expected legal challenges.

The Environmental Protection Agency regulation, called the Clean Power Plan, seeks to curb nationwide electricity emissions 32 percent below 2005 levels by 2030 by setting standards for power plants. The reductions will be achieved largely by shifting the power sector away from coal, which supplies 39 percent of United States electricity, and toward renewable energy and natural gas.

"This is one of these rare issues that ... if we don't get it right, we may not be able to reverse or to adapt sufficiently. There is such a thing as being late when it comes to climate change. But that shouldn't make us hopeless," President Obama said at a White House ceremony.

Environmental groups and Democrats cheered the rule, which Obama called "realistic, achievable and still ambitious." But GOP and industry critics that have long assailed the effort doubled down Monday and vowed to scuttle the regulation through legislation and lawsuits.

"With the release of the finalized emission rules for power plants, the Obama administration is focused on cementing its radical environmental agenda at the expense of the American people. This rule will be too costly, unachievable and would place potentially billions of added costs on the backs of working and middle-class Americans across the country," said House Majority Leader Kevin McCarthy, R-Calif.

Industry groups and red states already filed lawsuits against the rule when it was in draft form, though a federal court dismissed the case because the regulation wasn't yet final. Opponents say the rule would increase energy costs and that it is illegal, as they contend the EPA lacks authority to require emissions reductions outside of individual power plants.

"Left in place are targets for replacing affordable energy with costly energy. These will burden Americans with increasingly high-costs for an essential service and a less reliable electric grid for delivering it," National Mining Association President Hal Quinn said.

But the Obama administration contends the rule will save consumers money — about $85 per household by 2030 — and save medical costs and lives by shuttering older, dirtier coal-fired power plants. Obama called on allies to defend the rule against backlash against groups that he said blasted the rule "long before the details of this Clean Power Plan were decided."

"Every time America has made progress, it's been in spite of these claims," Obama said.

Obama has increasingly viewed climate change as a way to solidify his presidential legacy. He wanted to get the rule completed in advance of United Nations climate negotiations set to begin in November in Paris, where he will try to leverage the rule to get carbon-cutting commitments from other countries.

"I am convinced that no challenge poses a greater threat to our future, to future generations, than a changing climate," Obama said.

Environmental organizations, public health groups and liberal Democrats praised Obama for crafting a regulation to address climate change in the face of opposition from GOP Congress that largely is skeptical of the role humans play in warming the planet. Most climate scientists say that greenhouse gases, mainly formed by burning fossil fuels such as coal, are driving manmade climate change.

"The Clean Power Plan is the single biggest action our country has ever taken on climate, because it tackles the single biggest source of our global warming pollution: dirty power plants. The Clean Power Plan also represents a huge step toward a clean energy future, because it dramatically ramps up wind and solar power," Environment America Executive Director Margie Alt said.