Story highlights Michael Bloomberg, Michael Brune: U.S. has made huge strides in reducing carbon emissions

That strengthens its hand at Paris climate talks, authors say

Former New York Mayor Michael Bloomberg is the U.N. secretary general's special envoy for climate change and cities and Michael Brune is executive director of the Sierra Club. The opinions expressed in this commentary are theirs.

(CNN) Here's some good news that many Americans may not realize: Domestically, we are winning the fight against the carbon pollution that drives climate change. And by doing so, we are giving President Obama a strong hand to play when world leaders gather at the U.N.'s climate summit in Paris in five weeks to negotiate a global agreement to limit carbon emissions.

To understand how the White House finds itself in this position of strength, think back to 2010, when Congress failed to pass a cap-and-trade bill. That seemed to end any hopes of making major reductions in emissions and demonstrating American resolve to the global community. But in fact, even though the bill did not become law, the United States has already exceeded the carbon reduction goals it aimed to reach.

Michael Brune

Michael Bloomberg

According to a study being released Wednesday by the Sierra Club and Bloomberg Philanthropies, 2015 U.S. economy-wide carbon emissions are even lower than they would have been had the bill passed. In fact, the United States can now say it has led the world in reducing carbon pollution over the last decade.

A primary driver is that over the past five years 130 coal-fired power plants have been retired and another 70 are preparing to retire over the next few years. Yes, cleaner energy sources have played an important role in reducing emissions. So did the Obama administration's tougher fuel efficiency standards for cars and trucks. But the biggest factor, as the new data shows, was the decline in coal use.

How did it happen? Market forces have been moving against the coal industry for some time, due to wind and solar becoming competitive, the industry cutting wasteful demand and the natural gas boom. But the decline in coal use also stems in large measure from citizens demanding cleaner air and action on climate change. People across the country joined with the Sierra Club and many other organizations in standing up for their right to breathe clean air. Five years ago, coal pollution helped kill 13,000 Americans a year. Now, that number is down to 7,500.

Read More