By MEAD GRUVERCHEYENNE, Wyo. (AP) a¿¿ Turns out the worst state for carbon dioxide emissions per person isn't smoggy California or bustling New York, but a place famous for its big, clear skies: Wyoming. But regulating greenhouse gases is a touchy subject in the least-populated state, which just recently received U.S. Environmental Protection Agency approval to do so. Wyoming also is the top coal-mining state by far, producing almost 40 percent of the nation's coal. Burning coal to generate electricity produces large amounts of CO2 a¿¿ in Wyoming, across the U.S., and in the Far Eastern countries where state officials have sought to open up new coal markets. Gov. Matt Mead made such a trip to Taiwan and South Korea last year. Meanwhile, he's called EPA efforts to curtail greenhouse emissions a "war on coal" and said at a recent forum he's skeptical about man-made climate change. "What he also says is we do have a responsibility to always do things better," Mead spokesman Renny MacKay said Thursday. "The coal industry has to be profitable if it's going to invest in the research and development of new technologies." MacKay highlighted the state's efforts to make its coal cleaner: $50 million allocated toward new coal-burning technology at the University of Wyoming and plans by the state to support a proposed $10 million X Prize to develop economically feasible carbon-capture technology at an operational coal-fired power plant. He said the EPA shouldn't impose rules that cripple coal-fired electricity by requiring still-unattainable greenhouse reductions, but, instead, should gradually implement rules as new technologies to cut carbon emissions become available. The stakes for Wyoming are high. Minerals taxes on coal provided $1 billion to the state and local governments in 2012 and coal mining supports some 6,900 jobs in the state. Last year, Wyoming's coal production fell 3 percent amid more stringent environmental regulations and inexpensive natural gas, a cleaner fuel source in growing use by electric utilities.