NAS: act now to reduce global warming.

Despite uncertainties in the science of predicting global climate change, the National Academy of Sciences (NAS) urges immediate action to curb greenhouse-gas emissions by reducing fossil-fuel consumption, promoting energy conservation, and improving solar and nuclear-energy technologies. For a very low cost, says NAS President Frank Press, the United States could reduce its greenhouse-gas emissions by 10 to 40 percent.

According to White House Science Adviser D. Allan Bromley, the NAS recommendations "are very similar to actions already taken or being proposed by the Bush administration." Both Press and Bromley testified before the Senate Committee on Commerce, Science and Transportation last week.

"The possibility of ecological disaster due to an increase in global temperature is sufficient reason to act now," Press warned. Outlining recommendations in "Policy Implications of Greenhouse Warming," an NAS report released April 10, he advocated a variety of low-cost steps aimed at reducing emissions of the major greenhouse gases -- carbon dioxide, methane, chlorofluorocarbons and nitrous oxide.

For instance, the academy report recommends adopting nationwide energy-conserving changes in building codes for residential and commercial structures, boosting the average automobile-fuel efficiency 18 percent (to 32 miles per gallon) and substituting compact fluorescent lights for incandescent bulbs in homes and businesses.

Together, the measures described in the new report are designed to head off a predicted 1 [degree] to 5 [degrees] C increase in global temperature by the year 2050, Press said. Enactment of these steps -- which the report estimates would cost between $4 billion and $30 billion -- could reduce the heat-trapping equivalent of 3.6 billion metric tons of carbon dioxide emissions per year, or about one-third of last year's U.S. greenhouse-gas emissions.

However, the report cautions that even at reduced emission rates, total greenhouse gases might still increase if population and industrial activity increase faster than predicted.

The NAS recommendations "parallel" actions specified in the President's National Energy Strategy released in February, Bromley testified. But committee member Sen. Albert Gore Jr. (D-Tenn.) disagreed, charging instead that many administration policies are "simply in opposition to the recommendations in this report." He warned Bromley that "history will judge the Bush administration harshly if its current inactivity on global warming continues."

While the NAS report stopped short of calling for penalties and higher taxes for major producers of greenhouse gases -- which some European nations have imposed -- environmental groups generally approve of the new recommendations. "This report should remove any lingering doubts that more time is needed to study global warming before we act," says William A. Nitze, president of Alliance to Save Energy.

Though most environmental groups support the NAS report's call for increased funding for development of new renewable technologies, many also object to some of the report's higher-cost recommendations, including the replacement of most fossil-fueled power plants with a new generation of lightwater nuclear reactors now under development. "We are strongly opposed to any effort that puts forth nuclear power as a panacea for the greenhouse effect," says Eileen Quinn of the Union of Concerned Scientists.