The first phase of the program would see a strategic shift in three years to nuclear, solar, wind, biomass power and clean coal technologies - with investment opportunities worth as much as 3 trillion yuan, Liu said. Phase two encompasses the period up to 2020 and would entail far more investments, he pointed out.

The research panel of the National Development and Reform Commission (NDRC), the nations' top planner, has predicted that China's clean energy development strategy would create huge investment opportunities for private and State investors.

China needs to spend at least 40 trillion yuan by 2050 to go 'green', according to the expert panel of the NDRC's Energy Research Institute.

"Roughly, we need to spend an extra 1 trillion yuan every year to raise energy efficiency," Bai Quan, a senior member of the panel, said. The panel will publish its research findings on China's low-carbon roadmap this month.

Explaining the mathematical model that his colleagues had built, Bai said the money would be mainly used to introduce technologies that raise the energy efficiency of end-users in industry, construction and transportation.

If the investment showed results, it would mean the country's per capita greenhouse gas emissions would increase by only 50 percent during the 2010-50 period - to 6 tons from the present 4 tons. Per capita emissions stood at 3.58 tons in 2004.

The target could be made a national goal, given that per capita income is expected to increase 10-fold to 200,000 yuan by 2050 from 20,000 yuan in 2010.

Jiang Kejun, another researcher at the NDRC institute, said the project would offer a low-carbon alternative for the consideration of top policymakers.

Low-carbon emissions should be made standard State policy, at least in the 13th Five-Year Plan (2016-20) if not in the 12th plan period itself, Jiang said.

He Jiankun said the country's carbon dioxide emissions were likely to peak in 2035, at 8.8 billion tons, when industrialization and urbanization would be in an advanced stage, compared with around 5.5 billion tons in 2010.

Spending on climate increased nearly 100%

But from 2035 to 2050, emissions would remain stable or decline marginally if the proper technological route was followed, He said. "This is our ideal carbon map," He said.

The government's stimulus effort has already won international recognition. The Washington-based World Resources Institute said recently that about 38 percent of China's stimulus package investment was "directly or indirectly" related to environmental protection.

The Ministry of Finance said that, between January and May, spending on environmental protection rose 93.5 percent over the corresponding period last year.

Despite the low-carbon roadmap and the central government's commitment to sustainable development, some regions in China had yet to make progress in "green recovery."

Li Ganjie, the vice-minister of environmental protection, said the central government would continue to pump enough investments into environmental protection. "But, I doubt whether the local governments would be able to fully implement these environmental standards," said Li.

To change the situation, He said the solution was to alter the assessment system of officials. "If we fire them when they fail in environmental protection and carbon reduction goals, our economy will see more sustainable development."