Several letters have appeared lately about global warming. The environmental impact side of carbon-based energy use has been debated to the point that the more important priority -- future availability of affordable energy -- has been pushed to the background. The key word is "affordable."

Theory holds that all the easy-to-extract oil reserves in the world have been discovered. Going forward, demand will outstrip supply due to world economic expansion. This will cause prices to escalate even higher than we saw last year.

Natural gas, like oil, is a diminishing resource. Consumption is up, due to new power plant conversion to gas. Facilities are being built to handle liquefied natural gas, but the construction and transportation costs weigh in heavily and add to the use cost.

Uranium also has a limited supply. One estimate states that if enough conventional reactors (not breeder reactors) were built to supply about one-half of the world's electrical energy consumption, the supply of uranium could be depleted within 30 years.

Coal supply is abundant, especially in North America (estimated 159-year supply), but air quality standards dictate that clean coal technologies will have to be applied in future uses. This increases the use cost.

The path forward is to develop supply in the short term and alternative sources of affordable energy for the longer term. One report states that to replace just 10 percent of U.S. coal-supplied power consumption would require as many as 40,000 wind turbines. How long would it take to construct these? Who could make them?

One thing is obvious. If we don't get focused on the real problem, high energy costs will diminish the quality of life we now enjoy -- and the quality of life that future generations anticipate.

Roger Bailey

Southern Pines