In his United Nations speech last week, President Obama made a commitment to lead the global effort to reduce the emissions that cause global warming. That was not only appropriate but necessary given this country's responsibility for the problem.

Among the major culprits are America's power plants, which produce more than 6 percent of the world's global-warming emissions. Only China produces more. In fact, in 2012, U.S. power plants produced more carbon dioxide pollution than South America, Canada, and Mexico combined.

That would change if America mothballed old-fashioned plants that use coal to generate electricity. A new Environment New Jersey report titled "America's Dirtiest Power Plants" says coal-fired facilities produced 74 percent of all power-plant pollution in 2012, but only 37 percent of the nation's energy.

Obama isn't just talking about the problem. The Environmental Protection Agency is working on implementation of a Clean Power Plan requiring plants to cut their carbon emissions by 500 million metric tons by 2030. That's equal to all of Canada's emissions in 2012. Of course, getting states to comply with the rule will be a taller order.

But given the U.S. role in global warming, that's not where the job stops. Obama acknowledged that the United States needs to do more, particularly when it comes to working with developing nations whose carbon emissions are rising as they become more industrial.

Whether global warming is real is no longer a question. It has been documented by scientists. And if we humans keep emitting greenhouse gases by burning fossil fuels, it's expected that sea levels will rise, thousands of miles of coastline will be submerged, dozens of coastal communities will disappear, and monster storms like Hurricane Katrina will become more intense.

That may not happen in our lifetimes. But as Obama said, "We cannot condemn our children, and their children, to a future that is beyond their capacity to repair; not when we have the means - the technological innovation and the scientific imagination - to begin the work of repairing it right now."

Those are strong words, but this nation has made strong statements before, only to pull back from reform in the face of opposition from industries that cite the impact on the economy and jobs.

They ignore the fact that alternative forms of energy produce jobs, too. Accelerating their use could accelerate job creation.