Worldwide energy demand is skyrocketing as carbon dioxide continues to build up in the atmosphere.

CO2, largely released by burning hydrocarbons to generate electricity, is blamed for global warming. The heating of the world is seen as a potential disaster whose magnitude can't be gauged.

Emerging economies have triggered an unprecedented surge in constructing air-polluting power plants. The Xinhua News Agency in China said that in the first 11 months of 2004 alone, plans were submitted to build 200 new coal-fired power plants. Greater competition for all sources of energy has caused the price of oil, uranium and many other commodities to soar.

Meanwhile, fears about melting ice caps, about running out of resources and about the dangerous health effects of air pollution force people everywhere to closely examine their energy reserves and options.

A good place for Utahns to begin is by thinking about the energy source the state has depended upon most heavily and for the longest period — coal.

A story recently circulated in the Capitol and in coal towns that Utah's once-enormous coal reserves are running out, that the state may have only around a dozen years' worth left. Others have countered that known deposits could last at least another half-century.

Is Utah really running out of coal?

"It's kind of a yes and no answer," says Michael Vanden Berg, a geologist with the Utah Geological Survey.

"Yes, the current mines are depleting their resources around the mines." Some mines are within a year or two of closing their portals because they are nearly out of coal, he said.

The vast majority of Utah's mining takes place in the Book Cliffs and Wasatch Plateau coal fields, Vanden Berg said. "They've been mined for a century or more. And so, yes, the coal in these two fields is beginning to run out."

James F. Kohler, chief of the Bureau of Land Management's Solid Minerals Office in Salt Lake City, recently told the Utah Geological Association that coal production in the state in 1985 was about 12 million tons. Now it's around 27 million tons. Since 1985, federal and state agencies have issued new leases on about 539 million tons of coal. (Leases give the legal right to extract resources from government or private land.)

Meanwhile, some mines were in places with few remaining reserves, causing a few to close. Central Utah mines still operating have these reserves under lease: Canyon Fuel Co., 128.5 million tons; Consolidated Coal, 40 million; PacifiCorp, 53 million; others, 89.6 million. The total is 311.1 million tons.

At a production rate of 27 million tons yearly, he noted, the amount under lease might last another 12 to 14 years. This is where claims come from that Utah has fewer than 15 years of coal mining left.