China is touting its carbon-limiting plan as a "major contribution" to the struggle against climate change, but its already massive greenhouse gas emissions will still rise for years to come.
The United States and Europe have announced plans to actually cut emissions of the greenhouse gases blamed for global warming, but China said on Thursday it would seek only to reduce emissions as a percentage of the economy.
That means that China's world-leading emissions of carbon dioxide will continue to soar along with its fast-expanding economy, albeit at a slower pace, experts said.
"We think it represents a relatively small move away from business-as-usual for China and still implies quite a large growth in emissions," said Nick Mabey, chief executive of British environmental think tank E3G.
He said that "actual emissions -- instead of doubling -- will grow around 50 percent".
However, others believe emissions will grow by an even greater margin, based on Chinese economic growth rates of 8-12 percent in recent years.
"That means under the target, emissions will 'only' double," Frank Jotzo, deputy director of the Climate Change Institute at Australian National University, said.
China said that by 2020, it would cut the amount of carbon dioxide emitted per unit of gross domestic product (GDP) by 40 to 45 percent compared to 2005 levels. That is essentially a pledge of greater energy efficiency.
With electricity demand soaring, China relies on carbon-belching coal to generate about 70 percent of its energy needs.
Beijing had previously announced plans to increase energy efficiency and the use of renewable and low-carbon fuels, and the new plan looks like merely an extension of those pledges, Jotzo said.
Still, while environmentalists called for more, China's announcement was broadly welcomed as a good start for the huge developing country in the run-up to Copenhagen climate talks next month.
China maintains its developing status exempts it from emissions cuts because its overriding goal is to reduce poverty among its 1.3 billion people.
But political concerns also prevent a deeper commitment.
China's top climate change negotiator Xie Zhenhua stressed Thursday the nation's "primary task" was economic growth.
The communist leadership, facing a gaping rich-poor divide and increasing social unrest, says it needs to maintain a minimum of eight percent GDP growth each year to maintain stability.
"Everyone would like to see China commit to an absolute limit but ... it doesn't want to limit its growth prospects," said Tom Grieder, Asia energy analyst at IHS Global Insight in London.
Xie declined to give a timeframe for when emissions would peak or estimate how much they would grow by 2020.
But even meeting the 2020 goals will be difficult, Greenpeace China climate campaigner Yang Ailun told AFP.
"(The target) means China will have to tackle its over-dependency on coal," Yang said, arguing that China needs an "energy revolution".
She called for a more aggressive push on renewable energy and a hefty carbon tax to discourage consumption -- something Beijing has been loathe to do out of concern for the economic impact.
China said it would push development of renewables, energy-saving technologies and nuclear power, and make unspecified adjustments to "fiscal, tax, and pricing" policies to meet the 2020 targets.
But observers noted that Beijing faces difficulty implementing nationwide initiatives due to vested interests, local resistance and widespread graft. And several existing energy-conservation initiatives have already foundered.
"That's the biggest hurdle. Many local officials don't do what the central government says," Grieder said.