Although scientists still disagree over whether the threat of global warming is an imminent problem, new findings by a team of Harvard researchers strongly suggest that current high levels of carbon dioxide in the atmosphere will profoundly alter the ecosystem.

The results of the study, coauthored by Timken Professor of Science Fakhri A. Bazzaz and Eric D. Fajer, a postdoctoral candidate at the Kennedy School's Center for Science and International Affairs, will be published in the January issue of Scientific American, scheduled to be released December 9.

The study reports that many types of plants tend to grow more quickly in a carbon dioxide-rich environment, but that these plants contain fewer nutrients than plants grown in a normal environment. Consequently, these nutrient deficient plants take longer to decompose, which in turn leaves fewer nutrients available in the ground for new plants in the spring.

In an attempt to determine the effects of atmospheric carbon dioxide levels on the ecosystem, Bazzaz and Fajer also examined the reactions of various insect populations to such nutrient deficient plants.

They found that butterfly larvae, which were fed leaves from nutrient deficient plants, had a higher rate of mortality and a slower rate of growth. Since insects constitute an important link in the food chain, lower populations of insects may have a huge impact upon animals and humans, they said.

Bazzaz said in an interview yesterday that he hoped that the general public would not ignore the results.

"This is not speculative beyond reason," he said. "It has a definite scientific backing."

The article was intended to educate the population about the importance of the global changes, said Fajer.

"The carbon dioxide increase will affect our children and our grandchildren," he said. "We need to do something about it."

Fajer suggested that society should quickly act to alleviate the alarming rise in carbon dioxide levels in the atmosphere.

"We need to practice energy efficiency and use alternative sources," he said. "We have to do research on energy sources that don't produce carbon dioxide."

Bazzaz added that alternative sources were not in widespread use now because they were not yet economically feasible.

"We consume so much oil and coal because they are so cheap," Bazzaz said. "Research can help to find economical and marketable alternatives."

Fajer said that although the public can have an immense influence over national energy policy, it does not think about environmental issues enough.

"People have the power of the vote," he said. "[But] people usually don't vote for the environment. They vote for their pocketbooks."