"If you're not going to use coal anymore what are you going to use?" he said he asks anti-coal advocates. "Well, they respond to you: new technology, solar and wind.

"My response is: 'Well, how does that work? and they say: 'I don't know but we need to study it,"' Harvey said in an interview during this week's Reuters Environment Summit.

"Well if it was really that easy, don't you think we'd have already done this? Do you think we would already have avoided the Clean Air Act and everything we've done to clean up coal over the years and gone automatically to that?" said Harvey, whose Pittsburgh-based company produces approximately 70 million tons of coal per year.

"There is a direct relationship between the use of coal and a healthy economy," he said. "When you quit using 50 percent of your electricity then we can talk. If you throttle back the use of coal and drive your base power costs up, you make all the products we make more expensive."

Asked how the industry viewed environmentalists' efforts to stop construction of new coal-fired power plants, which they blame for increasing greenhouse gas emissions, Harvey said: "Well, it's the whipping boy.

"I think the whole mantra of the environmental groups is: don't waste energy and if you make everything more expensive the theory is you use less. That's the underlying basis of their argument, but it's not the nature of the American public or probably anyone in the world," Harvey said.

Coal fuels approximately 50 percent of America's electricity generation, but environmentalists want to replace it with alternative sources, such as wind or solar, to meet future increased power demand.

Harvey said the problem lies also with the public's perception of coal as an outdated, dirty, 19th Century fuel.

"People have disconnected the use of coal from what they do in their everyday lives. They think that's what their grandparents used to do. They don't realize when they hit the light switch they hit Consol Energy."

Harvey said in the 1990's America decided it wasn't going to use coal any more. "The administration said coal would be done in 2005.

"Everybody believed it and natural gas went from a buck and a half a million (BTU) to US$10 a million based on throttling back coal and, guess what, now we're on short supply of natural gas, we overbuilt gas generation and you can't replace it with limited fuel sources."

Asked about clean-coal technology, he said: "Should we do something more with coal? Yes. Can we make it cleaner? Yes. But it's going to cost us and it's going to take time.

"This is no different from landing somebody on the moon, if the focus is there and the attitude is there, we'll get it done. What we need is people to agree to solve the problem, not just throw the baby out with the bathwater and say there's an alternative that nobody can describe."

Coal-to-liquid (CTL) technology would require US$2 billion to US$3 billion in research per year over 10 years, he estimates.

"Probably the best thing to do is take and bill the people who use the coal for power. Tack that as a fee on the use of power for coal and put it in a research institute. It costs the average family about US$5 a year and you will have funded the research," he said.