Seen by some as the last chance to save the planet, the United Nations climate talks in Copenhagen entered the final stage when 110 world leaders are arriving in the Danish capital to seek an agreement on a post-Kyoto regime.

China maintains any new treaties should be based on the Kyoto principle of "common but differentiated responsibilities" that commit industrialized nations to mandatory cuts in greenhouse gas emissions and limit the obligations of developing countries.

China announced ambitious plans last month to cut greenhouse gas emissions per unit of GDP by 40 to 45 percent by 2020 from the 2005 level.

"We think highly of China's emissions cutting target and its active attitude in international negotiations," said Li Lin, director of Conservation Strategies at the World Wildlife Fund (China).

"However, China will pay a high price for reaching the target," said Li.

As a developing country with a per capita GDP of US$2,770, less than a third of the world's average, China's road of low-carbon development would incur heavy costs in the short run.

Reaching the 45 percent target by 2020 would cost China US$30 billion per year over the next 10 years, said Zou Ji, a professor with the Renmin University of China.

In the first four years of China's 11th Five-Year Plan Period (2006-2010), the closure of high energy-consuming and high carbon-emitting plants led to the loss of 400,000 jobs, according to research by Zou's team.

The marginal cost of cutting emissions was set to rise as the economy recovered and more factories started production, and this would affect China's ability to raise incomes, reduce poverty and create jobs, said Zou.

China faced special difficulties in controlling greenhouse gas emissions with its large population and relatively low economic development level, said Xie Zhenhua, Vice Minister of the National Development and Reform Commission (NDRC) late November after the government announced the target.

About 150 million Chinese live in poverty, posing a daunting challenge in improving living standards.

Heavy industries with high carbon emissions accounted for 71 percent of China's industrial output in 2008, and coal accounted for 70 percent of energy consumption, according to the National Bureau of Statistics.

However, the government would adhere to its emissions cut target despite the difficulties, said Xie.

To reach the target, China must move away from the traditional development mode that featured high pollution and high emissions, said Zhou Dadi, a researcher of the NDRC.

In the past three years, the government had been eliminating outdated steel, cement and coke producers. By July, China had shut down small thermal power units capable of generating 54 million kilowatts, equal to 124 million tonnes of carbon dioxide emissions avoided, according to the NDRC.

By July, carbon dioxide emissions per unit of GDP were down 13 percent from the 2005 level. When the goal of 20 percent is realized next year, 1.5 billion tons of carbon dioxide could have been avoided during the 11th Five-Year Plan Period.

The government is also stepping up development of clean energies and renewable technologies.

By the end of 2008, China's installed capacity of hydro-electricity reached 172 million kilowatts, the highest in the world. The installed capacity of wind power doubled for three consecutive years. In 2008, China used a total of renewable energy equal to 250 million tons of standard coal, avoiding 600 million tons of carbon emissions, according to statistics of the National Energy Administration.

Jeff Huang, vice president of the Chicago Climate Exchange, says, "China is not only making progress in quantity of new energy used, but also in renewable technologies."

Counting on government support, more investment and great market potential, China is poised to transform from an importer of new energy technologies to an exporter, says Huang.

In the meantime, China has stepped up efforts to cooperate with other developing nations to combat climate change.

In the Fourth Ministerial Conference of the China-Africa Cooperation Forum in November, China announced aid for African countries to build more than 100 solar power, marsh gas and hydro-electricity projects.

Nick Nuttall, spokesman for the Nairobi-based United Nations Environment Programme, said earlier this month that the assistance China provided was conducive to Africa's sustainable development and diversifying the continent's economic growth patterns.