BEIJING China's ranking as top emitter of the main planet-warming gas, carbon dioxide, seemed confirmed by a Dutch report on Friday, putting more pressure on Beijing to come up with their own figures, experts said.
The finding from the Netherlands Environmental Assessment Agency (PBL) is the third published in English by either European or U.S.-based researchers to show China at the top.
It says China's CO2 emissions raced 14 percent ahead of the total emitted by the United States last year.
One of the report's biggest effects will be to put more pressure on the central government to speed up the process of tallying its own total greenhouse gas emissions.
"No matter how many of these kind of reports are released, you still need the confirmation from China to really confirm the story," said Greenpeace China's Beijing-based climate and energy campaign manager Ailun Yang.
Even without China's confirmation, Friday's report represented the consensus view, said Isabel Hilton, editor of bilingual Mandarin-English China Dialogue website, which publishes reports about China's environment.
The delay in Beijing's confirmation reflected reluctance.
"As the Chinese saying goes, the tall tree attracts the wind. The government is conscious that being the largest emitter by volume, along with a vigorous program of building coal-fired power stations, risks putting China at a moral disadvantage in international diplomacy," said Hilton.
The Dutch report ranked India, another fast-developing Asian giant with a population of more than one billion, as the third biggest national emitter, at eight percent of the global total.
Pressure is building to include big developing countries in global targets ahead of a U.N.-led meeting in Copenhagen in 2009, which is expected to forge a broader pact to fight greenhouse gas emissions to replace the Kyoto Protocol after 2012.
But experts, including the Dutch report writers, say that the third major academic analysis to place China top does not mean that the fast-developing nation is a global bad guy.
"To put things in perspective you should also look at national circumstances like emissions per capita and GDP (income) per capita, which is much smaller in the case of China," said PBL's senior scientist Jos Olivier.
As superficially attractive as national rankings are, the picture they give is somewhat misleading, said Gavin Edwards, head of Greenpeace International's climate campaign.
"We live in a globalised world with global trade. Take any random major corporation which has large outlets in the West, you'll find large manufacturing bases in places like China. So it's very hard to decide who those emissions belong to."
Announced just as a U.N.-sponsored meeting on emissions cuts winds down in Bonn, and a few weeks before a major G8 meeting on the issue in Japan, the ranking might further heat up global discussions.
"(China's ranking) will certainly increase pressure for developing countries to join a post-Kyoto regime," said Hilton.
"The developed countries are responsible for the past. The developing countries, as the ratings show, hold the world's climate future in their hands."
China accounted for two-thirds of last year's global 3.1 percent rise in carbon emissions, from consumption of fossil fuels and cement production, but China's per-capita emissions still lagged far behind those of the United States, at 5.1 and 19.4 tonnes per person respectively, Friday's report said.
While understandable, China's delays in facing the numbers could prove problematic for Beijing, said Elizabeth Economy, Deputy Director of Asia Studies and Fellow for China at U.S.-based Council for Foreign Relations.
"China has said that it will consider aspirational targets for reducing greenhouse gas emissions, but not hard targets until 2050, when it anticipates that its per-capita emissions may well match those of the U.S. today," Economy said.
"The world, of course, cannot afford such a delay."
(Additional reporting by Gerard Wynn in London; Editing by Emma Graham-Harrison, Gerard Wynn and David Fogarty)