Preliminary results of a Southern Company-sponsored study show careful, sustainable use of rain forests can provide a less expensive way to reduce atmospheric accumulation of man-made carbon dioxide, a greenhouse gas linked to possible global warming.

Southern Company recognizes the continuing debate on whether human activities may enhance the natural greenhouse effect. This research is a valuable step toward lowering the high cost of offsetting carbon dioxide emissions.

The study`s chief researchers - Harvard University/Smithsonian Institution economist Marco Boscolo, Harvard economist Theodore Panayotou and University of Wisconsin-Madison forest economist Joseph Buongiorno - examined a range of logging practices in terms of both their net timber profits and the amount of carbon dioxide absorbed by the trees and converted into wood fiber.

They found that management strategies resulting in significantly increasing amounts of stored carbon need not be prohibitively costly.

"This study is an early indication that encouraging preservation of the rain forest through sustainable use is a feasible way to offset carbon dioxide emissions," said W. Robert Woodall, Southern Company`s vice president of environmental policy. "In fact, sustainable use of rain forests may be the most cost-effective way to offset such emissions."

Because an essential component of the analysis is detailed demographic information on tropical forests, this study only recently became possible. Previously unavailable, this data was provided by a major international initiative carried out by the Smithsonian Tropical Research Institute`s Center for Tropical Forest Science. CTFS has been gathering baseline biological and demographic information from forests throughout the tropics.

The study was carried out in the rain forests of Malaysia and is based on data collected in collaboration with scientists at the Forest Research Institute of Malaysia. Southern Company sponsored the study and has provided $300,000 to CTFS for both the biological and economic study of forest dynamics and carbon storage.

Current logging practices lead to a large net loss in stored carbon. The researchers - using computer models that varied how often trees are cut, what size trees are cut and how much damage remaining trees suffer from the logging practices - devised forest management strategies that can significantly reduce losses in stored carbon.

"Done properly, selective harvesting of mature growth can make room for new growth and leave the forest largely intact," noted Woodall. "Such a sustainable approach to forest management is good for more than just the forests: It additionally provides local employment and long-term economic stability."

The study found that, from a strictly financial viewpoint aimed at maximizing timber profits, logging is best done on a 40-year cycle. The amount of carbon stored naturally in a Malaysian rain forest that is not logged is 222 tons per hectare (abut 90 tons per acre). If a forest is logged every 40 years, the amount of carbon stored decreases by about 84 tons per hectare (34 tons per acre).

The most inexpensive strategy to reduce losses in stored carbon involves felling trees every 50 years and limiting trees cut to those larger than about 30 centimeters (one foot) in diameter. Such a strategy increases the measure of carbon stored - known as net present carbon accumulation - by 2.5 tons a hectare (about 1 ton per acre), at a cost of $1.20 a ton.

A slightly more expensive strategy results in a massive increase in carbon stored. By incorporating reduced-impact logging methods with the previous strategy, net present carbon accumulation increases to 27 tons a hectare (about 11 tons per acre), at a cost of $5.50 a ton. Beyond about 30 tons per hectare, cost increases steeply.

Even the highest-cost strategy in the study is less expensive than carbon taxes already in place in Denmark, Finland, the Netherlands, Norway and Sweden. Carbon taxes imposed in these countries range from $16 a ton to $172 a ton.

"Rain forests are not going to survive solely on the basis of their emotional appeal," Panayotou noted. "We need strong economic arguments for their conservation. Their role as carbon sinks is just such an argument, and a good one too - the cost, in hard cash terms, of sustainable managed tropical forests with an emphasis on carbon storage is not great. We should start thinking of tropical forests as carbon sponges. In this way, we save the forests and, at the same time, counter the build-up of carbon dioxide in the atmosphere."

Atlanta-based Southern Company (NYSE: SO), the nation`s largest producer of electricity, is the parent firm of five electric utilities: Alabama Power, Georgia Power, Gulf Power, Mississippi Power and Savannah Electric. It also markets energy-related services and mobile radio services under the Southern name. Its Southern Energy Inc. subsidiary develops, builds, owns and operates power production and delivery facilities and provides a broad range of services in the U.S. and international markets.

Southern Company`s common stock is one of the 20 most widely held corporate stocks in America.