President Barack Obama unveiled his proposal Monday to slash carbon dioxide pollution from power plants 30 percent by 2030, one of the strongest actions ever taken by the United States government to fight climate change.

The 645-page regulation, proposed by the Environmental Protection Agency (EPA) and expected to be final next year, takes fire at coal, one of the nation's largest sources of carbon emissions. It is Obama's last opportunity to make a significant impact on global warming after failing to push a sweeping climate change bill through Congress in his first term.

Under the rule, according to The New York Times, coal plants will be given the chance to reduce their carbon emissions rather than immediately shutting them down. Such changes may include installing new wind and solar generation or energy-efficiency technology and starting or joining state and regional "cap and trade" programs, in which states agree to cap carbon pollution and buy and sell permits to pollute.

EPA officials hope this flexible approach will make more of an impact, especially considering Obama pledged that the United States would cut its greenhouse gas pollution 17 percent from 2005 levels by 2020, and 83 percent by 2050.

"The glue that holds this plan together - and the key to making it work - is that each state's goal is tailored to its own circumstances, and states have the flexibility to reach their goal in whatever works best for them," EPA Administrator Gina McCarthy said, according to the New York Daily News.

Power plants account for about a third of the annual emissions and contribute to the United States' rank as the second largest contributor to global warming on the planet. There are undoubtedly skeptics out there, some worrying that the planned changes will drive up electrical prices, but the Obama administration insists that his rule to limit carbon pollution will actually boost the economy by $43 billion to $74 billion, Bloomberg Businessweek reported.

The 30 percent reduction represents an average, so states can cut carbon emissions at levels either greater or less than that overall figure.

"This momentous announcement raises the bar for controlling carbon emissions in the United States," Andrew Steer, president of the World Resources Institute, said, adding, "These new standards send a powerful message around the world."