The cries of protest have been fierce, warning that President Obama’s plan to cut greenhouse gases from power plants would bring soaring electricity bills and even plunge the nation into blackouts. By the time the administration is finished, one prominent critic said, “millions of Americans will be freezing in the dark.”

Yet cuts on the scale Obama is calling for — a 30 percent reduction in emissions from the nation’s electricity industry by 2030 — have already been accomplished in swaths of the country.

At least 10 states cut their emissions by that amount or more between 2005 and 2012, and several other states were well on their way, almost two decades before Obama’s clock for the nation runs out.


That does not mean these states are off the hook under the Obama plan unveiled this week — they will probably be expected to cut more to help achieve the overall national goal — but their strides so far have not brought economic ruin. In New England, a region that has made some of the biggest cuts in emissions, residential electricity bills fell 7 percent from 2005 to 2012, adjusted for inflation. And economic growth in the region ran slightly ahead of the national average.

“This is not going to be the Armageddon that some people think,” said Teresa Marks, director of the Arkansas Department of Environmental Quality.

In fact, with years left to reach Obama’s goal, and many states already heading in that direction, some of the loudest attacks on the plan are coming from those who contend it is not ambitious enough.

“I think it’s properly ambitious — for the first term of the Bill Clinton administration,” said Bill McKibben, the president and co-founder of 350.org, a group pushing for climate action. “Given the melting Antarctic, we obviously should be doing far, far more, but at least we’re finally started, and that’s to Obama’s credit.”


Europe, by contrast, is considering a 43 percent cut in emissions from power plants and other energy-intensive industries by 2030.

The Obama administration’s plan is not expected to become final until next year. Once it does, intense political and legal opposition is likely to follow, especially from the coal industry and from states run by Republican governors and legislators.

But even in states that have made big cuts, the Obama plan is provoking some wariness, with officials there pointing out that the plan would saddle them with stringent targets requiring them to go further.

Yet many of the states that are most dependent on coal — and have made the least effort to cut greenhouse gases — were given only moderate targets.

“Just because we’ve led in this effort doesn’t mean we should have to do as much or even more than states that haven’t even started,” said Larry Wolk, executive director of the Department of Public Health and Environment in Colorado.

The administration argues that some of the most coal-dependent states have fewer options, especially a shortage of power plants that use natural gas and can help displace coal.

As for the states that have already made headway, “we were asking states to continue doing what they were already doing,” said Joseph Goffman, senior counsel in the Environmental Protection Agency’s Office of Air and Radiation.

Willingness aside, some states are simply unsure how they will meet Obama’s targets.


South Carolina, for instance, was assigned a steep carbon- reduction goal. But officials of Santee Cooper, the state-owned utility that is South Carolina’s largest power supplier, say the options to meet it are limited. Natural gas supplies are constrained by a dearth of pipelines, and the wind turbines that are rapidly sprouting elsewhere are not practical because of the state’s placid weather, said Mollie Gore, the utility’s spokeswoman.

“This will hurt South Carolina because it will drive up power costs and send industries packing — it’ll cost jobs,” she said.

Opponents attacked Obama’s plan in vociferous terms this week, with the claim about Americans “freezing in the dark” coming from Joseph Bast, president of the Heartland Institute, a Chicago group skeptical of climate change.

But more optimistic assessments of the plan came from utility executives and many state officers who would have to carry it out.

“I predict this will be far easier and far faster and far cheaper than most people realize,” said Hal Harvey, chief executive of Energy Innovation, a research group.

Maine, Massachusetts, New Hampshire, and New York cut their power-sector emissions more than 40 percent from 2005 to 2012, according to the Georgetown Climate Center, with Maryland close behind at 39 percent. The states are part of a nine-state project called the Regional Greenhouse Gas Initiative and, like much of the country, have benefited from the recent abundance of cheap natural gas.