That might have been conservative.
China's emissions of carbon dioxide, the most significant greenhouse gas, have exceeded those of the United States, according to a report released by the Netherlands Environmental Assessment Agency.
The study estimated that surging power demand from China's rapidly expanding economy caused CO2 emissions to rise by 9 percent in 2006. That increase, coupled with a slight U.S. decline, meant that China's emissions for the year surpassed those of the United States by 8 percent, the Dutch report said.
A top official of the International Energy Agency, considered the authoritative source on global energy use and fossil fuel emissions, said yesterday that there was little practical difference between his estimates and those by the Dutch agency.
"It is either this year or it was 2006 or it will be 2008," said Fatih Birol, the agency's chief economist. He said what is important is how China and the richer industrialized nations respond to the situation.
Neither the United States nor China has ratified the 1997 Kyoto Protocol setting limits on greenhouse gas emissions. And as recently as this month's Group of Eight summit in Germany, President Bush cited China as a reason for his continuing to oppose mandatory measures, which critics say impose standards on the economically advanced nations but not on the developing world.
"We all can make major strides, and yet there won't be a reduction until China and India are participants," Bush said.
The Dutch report signals a remarkable turn of events for a country that, while the world's most populous, was an also-ran among the world's energy users until the past couple of decades, when the Communist government threw open the doors to a market economy. It underscores the urgency felt in other world capitals about reining in China's greenhouse emissions.
"It's just a continuous growth in the economy here that doesn't seem to slow down," said Jostein Nygard, a senior environmental specialist with the World Bank who is in Beijing to consult with energy officials about the emissions issue.
"When I've looked over these figures over the last year, I also have thought that we probably have underestimated how quickly China will surpass the United States as the world's largest CO2 emitter," he said.