LONDON/BEIJING Just last year experts at the International Energy Agency proposed a target for China's carbon emissions to peak in 2020 before declining if the world were to be saved from devastating climate change. Too late now.
Figures from energy firm BP showed earlier this year that Chinese emissions will steamroll through the Paris-based IEA's 2020 peak target next year, nearly a decade early, with no sign of slowing down.
China, which hosts U.N. climate talks next week for the first time, is promoting what it calls ambitious plans to boost energy efficiency and curb emissions. But its supercharged growth means even with rapid efficiency gains it cancels out other global efforts to combat climate change.
China already emits a quarter of the world's CO2, the main gas contributing to global warming, making it the world's top emitter ahead of the United States. Its emissions have more than doubled since 2000.
Higher emissions from China and other big emerging economies, plus the failure of rich countries to slash emissions, could pump greenhouse gases to levels which scientists say augur a dangerous rise in average global temperatures by more than 2 degrees Celsius (3.6 F).
The IEA's suggested target for China of 8.4 billion tonnes of CO2 per year by 2020, which would then fall, is in line with most other research for a safe peak, said Michel den Elzen at the Netherlands Environmental Assessment Agency.
But the latest figures released by BP and den Elzen's agency in June show China will hit that figure in a matter of months, rather than over the next decade.
"They are hitting that level earlier than expected because of their rapid growth the last decade," den Elzen said. "For meeting a 2-degrees target (of increasing global temperatures) such a high emissions rate is definitely bad news."
China's rapid economic growth is helping underpin a fragile global recovery, but it is also increasingly at odds with safe levels of greenhouse gases.
Policy makers recognize it is difficult to say what is a "fair" emissions target for China, which is rapidly pulling its huge population out of poverty.
"It's difficult to say that there's a benchmark for China which they should not exceed, because there are all kinds of issues, equity principles, on what you allocate for China," den Elzen said.
China does not control the agenda of next week's U.N. climate meeting in the northern port city of Tianjin, which runs from October 4-9. Beijing is not expected to announce any new carbon-cutting measures in the talks.
Still, the government could still use the conference to promote its own emissions curbing goals, to be incorporated into a five-year economic plan that starts from 2011.
China has resisted an absolute cap on its greenhouse gas emissions, like those developed countries are expected to implement. It says a cap would be unfair because it contributed less to the problem historically, its emissions per capita are still relatively low and it needs leeway to grow its economy.
Instead, its focus is on reducing "carbon intensity" -- the amount of the main greenhouse gas, carbon dioxide (CO2), emitted for each dollar of economic activity. It plans to reduce this by 40-45 percent by 2020 compared to 2005.
But even with such big efficiency gains, China's expected rapid economic growth will push its absolute volume of emissions to between 9.6 and 10.1 billion tonnes of CO2 per year by 2020, compared with 5.2 billion tonnes in 2005, according to a study from the Chinese Academy of Sciences.
Its emissions rose about 9 percent last year, faster than any other major economy. If sustained that rate "would torpedo efforts for the global 2 degrees target," said Malte Meinshausen, from the Potsdam Institute for Climate Impact Research (PIK).
The emissions projections underscore the wrenching economic shifts that China would have to achieve in order to help contain global CO2 levels at a point less likely to trigger worsening droughts, floods and extreme weather.
Even without an absolute cap, China's carbon intensity target will be tough, government officials and advisers say.
"Without a fundamental transformation of the development model and substantial adjustment of the industrial structure, China will find it impossible to achieve the 2020 emissions reduction goal," said the Chinese Academy of Sciences study.
China's new five-year plan and a follow-up one for 2016-2020 will detail how to reach the intensity goal and shift to low-carbon growth. But it is struggling to meet an existing target to cut energy intensity by 20 percent from 2005-10.
The most energy wasteful plants have mostly already been shut under that plan, and achieving further improvements will require more refitting of factories and plants and other more expensive measures, said Deborah Seligsohn, a Beijing-based climate policy expert working for the World Resources Institute.
China has won plaudits for investing in clean energy, making it the world's biggest wind power market last year, but a big majority of its energy will continue to come from high-carbon coal, at 69 percent and 64 percent in 2009 and 2015 respectively, according to national forecasts.
China could opt for a more stringent greenhouse gas goal from 2016 if it found the costs of carbon cutting and energy saving fall and other big emitters also took steeper cuts, said Barbara Finamore, Director of the China Program at the Natural Resources Defense Council, a U.S. environmental group.
The country will face mounting international pressure.
"They've just announced an increase in carbon emissions which is the same scale as the entire carbon emissions of the United Kingdom," said British energy and climate change secretary Chris Huhne last week.
"All the carbon emissions reductions throughout the world are effectively canceled out by China's increase."
-- Additional reporting by Jackie Cowhig in London