China, the leading global carbon emitter, will account for about 29 per cent of total global emissions by 2030, according to the US Energy Information Administration.
It had announced on November 26 that it would cut carbon emissions per unit of its gross domestic product by between 40 per cent and 45 per cent by 2020 compared with 2005 levels.
The pledge, however, raised many questions about how the reductions would be verified, the Washington Times reports.
Xie Zhenhua, vice director of the National Development and Reform Commission, China's top planning body, said China's carbon-intensity goals would be subject to domestic accountability systems that he did not specify. He said the goals would not be internationally binding nor subject to foreign verification.
The carbon goals will be part of China's next five-year plan but won't go into effect officially until 2011, when that plan begins and likely will take time to implement.
China will "reduce the speed of our emissions rise," but still needs to balance environmental and economic factors, Xie said.
According to the Beijing office of the World Wildlife Fund, China's new policy - if fully implemented - would prevent about four billion metric tons of carbon dioxide from being released over the next decade, slowing the rate of emissions growth slightly but not markedly diverting China from its upward trajectory.
On Thursday, India announced a similar goal of cutting emissions intensity by 20 per cent to 25 per cent from 2005 to 2020.
Like China, India's carbon cuts would be relative to GDP.
A Price Waterhouse Coopers report released Dec. 1 said that the United States, the European Union, China and India would account for 63 per cent of global carbon emissions between 2000 and 2050.
The report also stated that at the current rate of emissions growth, the global "carbon budget" that needs to be met during that period to prevent the worst effects of climate change would be expended in the next 16 years.
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