Limping economy leads to drop in air pollution

WASHINGTON -- A poor economy and high electricity costs in the West have produced an unusual environmental bonus, the government says: In 2001, emissions of heat-trapping greenhouse gases declined for the first time in a decade.

Still, the trend of annual increases in such gases -- mostly carbon dioxide from burning fossil fuels -- is expected to continue under future economic growth.

The Energy Information Administration reported that in 2001 pollution linked to climate change declined by 1.2 percent, but it also forecast a likely annual 1.5 percent increase in those same emissions through the year 2020.

The EIA, a statistical arm of the Energy Department, reported that 1,883 million metric tons of greenhouse gases were released in 2001, a 1.2 percent decline from 2000. It was the first such reduction since 1991, when emissions were 0.6 percent lower than the previous year.

Carbon dioxide, which comes from burning fossil fuels, accounted for 82 percent of all greenhouse gas releases. Other gases linked to global warming include methane, nitrous oxide and sulfur hexafluoride.

In 2001, the EIA said, the decline in heat-trapping gases was caused by a combination of factors that resulted in less use of fossil fuels:

A 3.5 percent decline in overall economic growth.

A 4.4 percent reduction in manufacturing output.

An unusually warm winter that curtailed demand for heating oil and natural gas.

A drop in electricity demand, especially in the West, were high prices caused people to conserve.

Greenhouse gas emissions in 2001 still were 11.9 percent higher than they were in 1990.

, when 1,683 million metric tons were released into the atmosphere. And the downward trend is unlikely to last.

A separate EIA study predicts that with current expected energy growth -- even with some increased efficiencies and conservation -- carbon dioxide emissions will increase by about 1.5 percent a year through 2020, and possibly beyond.

This would mean 2,237 million metric tons of carbon-equivalent greenhouse gas emissions by 2020, says the EIA, or about 19 percent more than the 2001 emissions.

A United Nations-sponsored panel of climate experts has said that if the amount of carbon dioxide and other greenhouse gases is not reduced, the concentration of these heat-trapping gases in the atmosphere could cause as much as a 10.5 degree Fahrenheit warming of the earth by the end of this century, causing dramatic climate changes.

A treaty negotiated in 1997 in Kyoto, Japan, would require industrial countries to reduce greenhouse gas emissions to below 1990 levels by 2012.

The United States has not ratified the treaty and President Bush has rejected it as too costly to the U.S. economy. Instead, he has announced a program working with industry to improve efficiency and find other ways to help curtail the growth of emissions.