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.