WASHINGTON — Coal industry officials came to Capitol Hill on Wednesday with two messages for Congress: Coal is an important energy source that’s essential to the nation’s prosperity, and safety remains a serious issue in the wake of a mine explosion in West Virginia that killed 29 people.

At a House committee hearing, the CEOs of the country’s top three coal companies fielded safety questions, but also addressed environmental concerns, especially greenhouse gas emissions responsible for climate change.

Last week’s disaster only increases questions about the future of coal, said Rep. Shelley Capito, R-W.Va.

Said Michael Carey, president of Ohio Coal Association, “Safety and environmental cooperation are core assets, core values for us.”

Safety will be the topic of a congressional hearing April 27, which could mark the first public appearance of Massey Energy CEO Don Blankenship, whose Upper Big Branch mine was the site of last week’s explosion.

At the hearing Wednesday, Carey appeared along with Steven Leer, chairman and CEO of St. Louis-based Arch Coal Leer, and executives from Peabody Energy Corporation and Rio Tinto.

“Coal is being used and will continue to be used around the globe,” said Leer. “Coal helps billions of people around the world enjoy a higher standard of living than would otherwise be possible.”

There was little debate that coal has a central role in the country’s energy future. Coal mining accounts for about 80,000 U.S. jobs and provides approximately 23 percent of the country’s electricity. Coal also produces more greenhouse gas emissions per unit of energy than any other major fuel source.

“I believe there is a successful future ahead for the coal industry, centered on safer and cleaner practices for your fuel, your workers, and for the Earth,” committee chairman Edward Markey, D-Mass., told the industry leaders.

How to get there, however, is a source of contention.

President Barack Obama has made clear his preference for comprehensive climate legislation, but in the meantime the Environmental Protection Agency is moving ahead with regulations. In October, the agency announced plans to regulate greenhouse gas emissions from the country’s largest emitters. And earlier this month, the EPA announced new permitting guidelines for Appalachian mountaintop removal mining.

“The Obama administration’s regulatory assault on energy production, and the war on coal in particular, is creating a de facto Obama energy tax on all American families,” said Carey of the Ohio Coal Association.

Supporters of action to limit greenhouse gas emissions say the industry has a choice.

“If you will take this lifeline that we have now sent the industry in this bill by sending billions of dollars to support research and development, then coal can have a future,” said Rep. Jay Inslee, (D-Wash.) “And if you don’t, it won’t.”

That “lifeline” is $60 billion for technology that would capture and store carbon emissions, a provision written into the climate bill passed by the House last summer. Although the industry sees this technology as its future, it is hesitant about the emissions caps that are also in the bill because the technology has not yet been proven.

“Affordable technology should be available before regulation,” said Gregory Boyce of Peabody Energy, the largest American coal company. “We have to take the time to get this right.”

Supporters of a cap on emissions, however, point to the 1990 Clean Air Act, which placed a cap on the emissions that cause acid rain. Emissions fell faster and at a lower cost than predicted.

The hearing also included a round robin about the science of climate change. Although the witnesses acknowledged that the atmosphere has seen a recent spike in carbon dioxide concentrations, only Rio Tinto, which has been divesting itself of U.S. coal assets, declared human activity as a major factor in the increase.