In his weekly address, Mr Obama previewed the announcement of new pollution rules that will serve as the cornerstone of his campaign to combat climate change.
The president said: "There are no national limits to the amount of carbon pollution that existing plants can pump into the air we breathe. None.
"We limit the amount of toxic chemicals like mercury, sulphur, and arsenic that power plants put in our air and water. But they can dump unlimited amounts of carbon pollution into the air.
"It's not smart, it's not safe, and it doesn't make sense."
The rules would allow states to require power plants to make changes such as switching from coal to natural gas or enact other programmes to reduce demand for electricity and produce more energy from renewable sources.
The Environmental Protection Agency (EPA) will make public specifics on the new rules for the first time on Monday.
The agency's aim is to tackle the single largest source of the pollution blamed for heating the planet - carbon dioxide emitted from power plants.
The plants produce about 40% of the electricity in the nation and about one-third of the carbon pollution that makes the US the second largest emitter of greenhouse gases.
But critics say the rules will kill jobs, drive up electricity prices and force power plants across the country to close their doors.
The timing of the announcement - just months ahead of the midterm elections - is also a source of concern for politicians on both sides of the aisle.
Representative Nick Rahall, a Democrat from West Virginia who faces a tough re-election bid in November, said on Thursday that while he did not have the details, "from everything we know we can be sure of this: It will be bad for jobs".
West Virginia gets 96% of its power from coal.
Also sparking debate is the use of a 1970 law that the Obama administration cites as giving the president executive powers to implement the rules without congressional approval.
Mr Obama was forced to rely on the Clean Air Act after he failed to get Congress to pass a new law during his first term in office.
The move is expected to provoke a messy and drawn-out fight with states and companies that produce electricity.
Michael Gerrard, director of the Center for Climate Change Law at Columbia University, said: "It's going to be like eating spaghetti with a spoon. It can be done, but it's going to be messy and slow."
Mr Obama attempted to dismiss critics in his address on Saturday, saying "special interests and their allies in Congress will claim that these guidelines will kill jobs and crush the economy.
"Let's face it, that's what they always say."