In a conference call involving representatives of public health groups, Obama asserted that “climate change is real” and “has serious impacts.” He predicted that electricity bills “will shrink as these standards spur investment in energy efficiency, cutting waste and ultimately we’re going to be saving money for homes and for businesses.”

“Now, I promise you, you will hear from critics who say the same thing they always say, that these guidelines will kill jobs or crush the economy,” Obama said. “What we’ve seen every time, is that these claims are debunked when you actually give workers and businesses the tools and the incentive they need to innovate.  When Americans are called on to innovate, that’s what we do — whether it’s making more fuel-efficient cars or more fuel-efficient appliances, or making sure that we are putting in place the kinds of equipment that prevents harm to the ozone layer and eliminates acid rain.”

“At every one of these steps, there have been folks who have said it can’t be done.  There have been naysayers who said this is going to destroy jobs and destroy industry. And it doesn’t happen because once we have a clear target to meet, we typically meet it. And we find the best ways to do it.”

Under the proposal, states will be given a year to develop plans to meet EPA carbon reduction targets. States will be provided with the authority to meet the standards in several ways, including via power plant improvements, switching from coal to natural gas, improving energy efficiency and embracing renewable energy in areas outside of the coal-fired plans. States that fail to settle on effective plans will have one implemented by the EPA.

McCarthy said failing to act to reduce carbon emissions is already costing the U.S. money, noting that 2012 was the second most expensive year in U.S. history for natural disasters, which some scientists believe could be related to global warming.

“Even the largest sectors of our economy buckle under the pressures of a changing climate and when they give way, so do businesses that support them, and local economics that depend on them,” McCarthy said. “As our seas rise, so do insurance premiums, property taxes, and food prices. If we do nothing, in our grandkids’ lifetimes, temperatures could rise 10 degrees and seas could rise four feet.”

“This is not just about disappearing polar bears or melting ice caps,” she said. “This is about protecting our health and our homes. This is about protecting local economies and jobs.”

Despite objections, polls establish that most people approve of the idea of the federal government reducing greenhouse gas emissions even if it results in higher energy costs. A Washington Post-ABC News Poll determined that 70 percent of those surveyed support carbon limits on existing power plants and expressed a willingness to pay an extra $20 a month to do so.

Foes already are talking about filing suit to halt implementation but that could prove difficult. The U.S. Supreme Court in a number of recent rulings has held that the EPA has broad authority to regulate emissions.

In a 6-2 ruling on May 3, the high court held that the EPA has the authority to regulate emissions produced by coal-fired power plants in order to protect downwind states from deleterious effects of pollution.