Carbon Emissions Exceed Highest Assumptions Used in Climate Change Studies

Global emissions of carbon dioxide are growing at a faster clip than the highest rates used in recent key UN reports.

CO2 emissions from cars, factories, and power plants grew at an annual rate of 1.1 percent during the 1990s, according to the Global Carbon Project, which is a data clearinghouse set up in 2001 as a cooperative effort among UN-related groups and other scientific organizations. But from 2000 to 2004, CO2 emissions rates almost tripled to 3 percent a year - higher than any rate used in emissions scenarios for the reports by the Intergovernmental Panel on Climate Change (IPCC).

If the higher rate represents more than a blip, stabilizing emissions by 2100 will be more difficult than the latest UN reports indicate, some analysts say. And to avoid the most serious effects of global warming, significant cuts in CO2 emissions must begin sooner than the IPCC reports suggest. At the moment, no region of the world is "decarbonizing its energy supply," the analysis says.

The Global Carbon Project's calculations should be viewed with caution, says Michael Oppenheimer, a climate-policy specialist at Princeton University in New Jersey. Economies have been recovering from a recession at the turn of the millennium. And a spike in natural-gas prices - of uncertain duration - has given coal a second wind in developed countries. These short-term factors have probably contributed to the growth in emissions rates, he says.

Yet longer-term forces may be at play to sustain the high emissions rates. For instance, "There is concern among many experts that factors such as China's continued, very rapid coal-based growth may not be a blip that would turn around," he says.

The analysis is the Global Carbon Project's first cut at an annual effort to report on trends in CO2 emissions and the factors contributing to them, says Christopher Field, a scientist with the Carnegie Institution of Washington.

"We're trying to figure out a small set of numbers that give people a clear picture" of what's happening, says Dr. Field, a member of the Global Carbon Project's science steering committee and a co-author of the analysis, which appears in Monday's edition of the Proceedings of the National Academy of Sciences.

The analysis comes at a time when negotiators for the G-8 group of leading industrial countries have been trying to work out the wording of a section on climate change, proposed for the final declaration at the group's meeting in Germany next month. Last week, US negotiators red-penciled key portions, severely weakening the statement.

The analysis also comes as countries prepare for a new round of UN-sponsored climate talks, scheduled for December in Bali. Negotiators are trying to establish a track for talks that would provide a seamless transition between the 1997 Kyoto Protocol's first reporting period, which runs from 2008 to 2012, and a new international regime to combat global warming that would follow - one in which developing countries would start taking an active role.

So far, developing countries account for only about 23 percent of emissions accumulated since the start of the Industrial Revolution. But they also account for 73 percent of the global emissions growth in 2004. This has been largely driven by China's explosive growth.

In trying to figure out how emissions-reductions burdens are apportioned, which number should dominate?

"There are very difficult discussions at the international level that must be dealt with," acknowledges Andrew Weaver, a climate scientist at the University of Victoria in British Columbia and chief editor of the Journal of Climate.

In broad terms, growing population and rising per capita economic growth have fueled the increase in emissions rates, Field explains. In addition, he says, two trends appear to be taking hold. Globally, the amount of energy used per unit of gross domestic product is leveling or increasing after years of decline. This could mean that gains in energy efficiency are slowing. It could also mean that the growth of heavy industry in developing countries is offsetting the shift to less energy-intensive activities in develped countries.