The Obama Administration’s decision to force the nation’s power plants to reduce their carbon emissions by about a third over the next decade and a half is overdue but welcome. For the past twenty years, the United States has been talking about tackling climate change, but, relative to some other advanced countries, its actions have been timid and insufficient. If the new Environmental Protection Agency regulations survive the inevitable challenges they will face in Congress and in the courts, the United States will finally start to live up to its verbal commitments. That by itself won’t stop climate change, but it could open the way to a truly meaningful international effort.

In this country and in many others, coal-burning power plants are the biggest source of carbon emissions. The second biggest is auto emissions. In 2012, the Obama Administration ordered carmakers to raise the fuel efficiency of cars, setting a target of 54.5 miles per gallon, on average, by 2025. Now the Administration is tackling the issue of coal. There had been talk that the Environmental Protection Agency would force power plants to reduce their carbon emissions by twenty per cent, relative to 2005 levels. In actuality, the E.P.A. is aiming for a cut of thirty per cent by 2030—a target that could lead to the closure of many older coal plants.

If the new rules for power plants and the fuel-emissions standards are both maintained and adhered to, the Administration says, the United States will be on track to meet the targets that President Obama set in 2009, when he pledged, as part of a United Nations accord, to reduce U.S. greenhouse-gas-emission levels seventeen per cent by 2020 and eighty-three per cent by 2050, relative to the 2005 level. Of course, this calculation is a hypothetical one. Congress, ever since it refused to ratify the 1997 Kyoto agreement, has blocked a number of efforts to tackle climate change, including a cap-and-trade bill that would have set an over-all limit for carbon emissions. With the midterm elections on the horizon, its members are unlikely to have a general change of heart now.

Republicans, energy-industry executives, and some Democrats in coal-mining areas accuse the Administration of using the E.P.A. to make an end-run around Congress and launch a “war on coal.” The Administration denies this, pointing to the possibility of upgrading older plants with more efficient turbines that burn less fuel, and to the development of carbon-sequestration techniques, which are currently in an experimental stage. But, with plenty of cheap shale gas available, power utilities are likely to accelerate the recent trend of closing coal plants and replacing them with cheaper gas-powered plants. “The era of coal is coming to an end,” Chris Faulkner, the chief executive of Breitling Energy, a Texas-based oil-and-gas company, told the Times. “We are entering the era of natural gas.”

That may be an exaggeration. Given the ever-rising demand for energy, and the vast global stocks of coal, it seems unlikely that mankind will let it sit in the ground forever. The new rules will give the energy companies and other interested parties a big incentive to develop cleaner ways of using coal and of capturing and storing its emissions. For now, though, natural gas, which mainly consists of methane, does appear to be the future.

Of course, burning methane also generates carbon emissions. But it’s cleaner than burning coal, and President Obama has hailed natural gas as “the transition fuel that can power our economy with less carbon pollution.” Still, many environmentalists are also vigorously opposed to the technique that is used to extract gas from underground rock formations—hydraulic fracking.

Monday’s announcement will give another boost to fracking, which may prove controversial in some circles. However, many big environmental groups hailed the new emissions targets, which Dallas Burtrow, a senior fellow at Resources for the Future, has described as “the most significant action” any President has taken on climate change. Mary Anne Hitt, the director of the Sierra Club’s Beyond Coal campaign, wrote in a blog post that “this new standard gives my daughter, and all today’s kids, a fighting chance at a safe and promising future.” And Keith Gaby, of the Environmental Defense Fund, said that the new E.P.A. rules “will kick-start a transition to a clean-energy and low-carbon future, which will lead to economic and health benefits for everyone.”

The new regulations will now be the subject of three-month comment period. It will be another couple of years, at least, before they go into effect. The E.P.A. has given the fifty states until June, 2016, to submit plans detailing how they intend to meet the new targets, and the agency is quick to stress that individual states will have a good deal of flexibility. Their options include closing or upgrading existing coal plants; switching to gas; developing alternative sources or energy; and joining regional cap-and-trade schemes, in which they agree to cap over-all emissions and trade pollution permits with neighboring states.

Opposition to the new rules will come in several guises. Lawyers for the power utilities will argue that the E.P.A. is going beyond its legal remit—to which the Administration will reply that the Supreme Court, in a 2007 ruling, said that the Clean Air Act gives the agency the authority to regulate air pollutants, including greenhouse gases. Resolving that dispute could well involve another trip to the Court. If Republicans take over the Senate later this year, they could push legislation stripping the E.P.A. of some powers—a proposal that Senator Rand Paul has championed—but President Obama would surely veto such a law.

In all likelihood, the ultimate fate of Obama’s plan will hinge on the 2016 Presidential election. For now, though, he has taken the initiative and put the onus on other countries that have used the lack of U.S. action as an excuse for doing nothing, or very little, to reduce their carbon emissions. China and India, for instance, are both building coal-fired power plants. If the new policy goes into effect, the United States, at long last, will be able to tell them “Do as I do” rather than just “Do as I say.” Since climate change is a global problem that can only be solved at the global level, that is an important step forward.

Photograph: Mark Wilson/Getty