Geotimes

From the Editor

This month our focus turns to the future -- specifically, the future supplies of oil and natural gas.

How long will supplies last? How reliable are the estimates? Will they become more expensive? Do experts agree on the estimated supplies? Is new technology likely to increase supplies and lower costs? The stories in this issue take a first cut at these quality-of-life questions. However, anyone looking for straightforward, simple and precise answers will be disappointed -- because the preparation of supply estimates requires various assumptions and choices from a variety of analytical tools. And supply estimates depend on "geology, economics, politics, technology and social science," to quote authors Thomas Ahlbrandt and Peter McCabe from our first feature. Such estimates, they add, require informed use.

Ahlbrandt and McCabe are U.S. Geological Survey (USGS) researchers and draw on the year 2000 USGS assessment of the world's conventional petroleum resources. In addition to presenting updated resource estimates, they conclude that "some recent claims of an imminent oil shortage cannot be supported." They go on to address the relations between reserves and resources and, in a particularly enlightening discussion, the geological, technological, business, political, economic and human factors that affect them.

In our second feature, William L. Fisher describes our energy resource journey from high-carbon wood to progressively lower-carbon coal, petroleum and finally natural gas. "Before we reach a carbon-free, nonfossil fuel economy," he says, "we have at least 50 years of transition ahead of us. This transition will be the methane economy." The methane economy is well underway with domestic consumption of natural gas increasing 22 percent during the 1990s. Natural gas now heats 50 percent of U.S. homes and fuels 95 percent of new power plants. As with petroleum, supply estimates depend on a host of factors, which Fisher addresses. Readers intrigued by the subject might want to compare Fisher's estimates with five separate U.S. natural gas resource estimates summarized in a an article by John B. Curtis and Scott L. Montgomery that appeared in the October 2002 AAPG Bulletin and was titled, "Recoverable natural gas resources of the United States: Summary of recent estimates".

Coalbed methane is a geologically distinct member of the natural gas family. It occurs within coal seams where it accumulated during and from the compaction and alteration of organic material to coal. In a special Energy and Resources page article, staff writer Lisa Pinsker reports that the estimated recoverable supply is 100 trillion cubic feet and that coalbed methane currently accounts for 7 to 9 percent of total U.S. natural gas production. One of the experts she interviewed predicts: "Unless there is continuous and sustained drilling, coalbed methane could peak as early as 2006."

Readers may question why we have left out the third fossil energy resource upon which we depend: coal, which represents a third of U.S. energy production and a quarter of its total energy consumption. Simply put, coal's abundance is not in question. Environmental concerns and technological limitations, not supply, will determine our future use of this resource. And that should probably be the subject of another issue.

Future supplies of petroleum, natural gas, or for that matter minerals and water, are in some respects prone to the same types of vulnerabilities as Enron's books. They are subject to inflation or deflation, misrepresentation, confusion, screw-ups and just plain mischief. Reliable and useful supply estimates require sound data, explicit assumptions, appropriate analytical tools, skilled geologists/geophysicists/engineers and a warning: "Read label carefully and use at your own risk."

Believe your compass -- but double check resource estimates.

Samuel S. Adams
Geotimes Editor-in-Chief


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