When the EPA tightened the national standard for ozone pollution last week, the coal industry and its allies saw it as a costly, unnecessary burden, another volley in what some have called the war on coal.

Since taking office in 2009, the Obama administration has released a stream of regulations that affect the coal industry, and more are pending. Many of the rules also apply to oil and gas facilities, but the limits they impose on coal's prodigious air and water pollution have helped hasten the industry's decline.

Just seven years ago, nearly half the nation's electricity came from coal. It fell to 38 percent in 2014, and the number of U.S. coal mines is now at historic lows.

The combination of these rules has been powerful, said Pat Parenteau, a professor at Vermont Law School, but they don't tell the whole story. Market forces—particularly the growth of natural gas and renewable energy—have "had more to do with coal's demise than these rules," he said.

Below is a summary of major coal-related regulations finalized by the Obama administration:

Most of the regulations didn't originate with President Barack Obama, Parenteau added. "My view is, Obama just happened to be here when the law caught up with coal. I don't think this was part of his election platform," he said.

Many of the rules have been delayed for decades, or emerged from lawsuits filed before Obama took office. Even the Clean Power Plan—the president's signature regulation limiting carbon dioxide emissions from power plants—was enabled by a 2007 lawsuit that ordered the EPA to treat CO2 as a pollutant under the Clean Air Act.

Eric Schaeffer, executive director of the Environmental Integrity Project, a nonprofit advocacy group, said the rules correct exemptions that have allowed the coal industry to escape regulatory scrutiny, in some cases for decades.

For instance, the EPA first proposed to regulate coal ash in 1978. But a 1980 Congressional amendment exempted the toxic waste product from federal oversight, and it remained that way until December 2014.

"If you can go decades without complying...[then] if there's a war on coal, coal won," Schaeffer said.

Parenteau took a more optimistic view, saying the special treatment coal has enjoyed is finally being changed by lawsuits and the slow grind of regulatory action.

"Coal does so much damage to public health and the environment," Parenteau said. "It's remarkable to see it all coming together at this point in time. Who would've thought, 10 years ago, we'd be talking like this about King Coal?"