Carbon dioxide emissions, a major contributor to global warming, jumped nearly 3% in the United States last year while declining in other industrialized nations, according to preliminary estimates released Friday.
The new figures, compiled by the U.S. Energy Information Administration, show that the United States released 1,558 million metric tons of carbon dioxide into the atmosphere in 2000, up 41 million tons from 1999. It was the biggest U.S. increase in years.
"That's an astonishingly large increase in a single year," said Robert Williams, a senior research scientist at the Princeton University Center for Energy and Environmental Studies. "The major reason is we don't have a policy to address this problem. We need to have a national target and some kinds of incentives [for business] and a regulatory system that will get us to meeting these national goals."
But Perry Lindstrom, an energy expert for the federal agency, said the 2.7% increase in carbon dioxide emissions is a "normal fluctuation" from the average annual growth rate of 1.5%.
The statistics are expected to increase pressure on the Bush administration to propose tough policies to rein in so-called greenhouse gas emissions. President Bush has been widely criticized by U.S. allies and environmentalists for his decision to end U.S. participation in the Kyoto global warming accord and for reversing a campaign pledge to regulate carbon dioxide emissions from U.S. power plants.
The agency attributed the increase in carbon dioxide emissions to several factors:
The U.S. economy continued to grow, increasing fossil fuel use across the board. Average temperatures dropped somewhat after several years of abnormally warm weather, increasing use of fossil fuels to generate heat. And a drought in the West reduced hydroelectric generation and boosted power production from fossil fuel plants.
Transportation-related emissions, mainly from cars and trucks, jumped 2.6%, while industrial emissions increased 1.8%, the agency calculated.
Williams said Americans' lifestyles are a major factor in the increased emissions.
"In transportation, we have had a major shift to sports-utility vehicles that are real intensive carbon dioxide emitters because they're gas-guzzlers," he said.
The Bush administration will have an opportunity later this summer to deal with that issue when it decides whether to tighten fuel-efficiency standards for cars and light trucks, including SUVs.
But, Williams said, it would take more than that to reduce emissions enough to avoid major disruptions of the global climate. In particular, he said, the country must find alternative energy sources that do not release large quantities of carbon dioxide into the atmosphere.
Electrical power plants, many of which are fueled by coal or natural gas, account for about a third of U.S. emissions of greenhouse gases. Nuclear power and renewable energy sources, such as wind and solar power, produce no carbon dioxide, but most experts say they won't replace fossil fuel power plants any time soon under current economic conditions.
China, the world's second-largest generator of greenhouse gases, has reduced its emissions by 17% since the mid-1990s by replacing old coal-fired power plants with more efficient ones. Over the same period, China's gross domestic product grew 36%. Britain's emissions have fallen to a 10-year low for much the same reason: It has replaced older power plants fueled by coal and oil with natural gas plants, which are more efficient and emit less carbon dioxide.
The latest increase in U.S. carbon dioxide emissions is expected to be a sore spot next month when Bush goes to the Group of 8 meeting of industrialized nations in Genoa, Italy, and a U.S. delegation attends the next session of the Kyoto accord negotiations--as a observer instead of a participant.
The United States is responsible for about a quarter of the world's total emissions of greenhouse gases.
White House spokesman Scott McClellan said Bush is concerned that global warming emissions are increasing. That is why he named a Cabinet-level task force to come up with "innovative ways to pursue market-based incentives and make use of new technologies to reduce greenhouse gas emissions by a significant amount in the years ahead," McClellan said.
Global warming is a phenomenon caused by increasing concentrations of carbon dioxide and other greenhouse gases in the Earth's atmosphere. The gases trap solar heat, causing surface temperatures to rise over time.
Scientists believe the long-term environmental effects could be profound, including increased drought in semi-arid regions, melting glaciers and higher sea levels.