Although it is not an easy task, China strives to put into practice the promise made last November before the Copenhagen Conference -- to cut its carbon dioxide emissions per unit of gross domestic product by 40 to 45 percent by 2020 compared with the level from 2005.

"The old path of economic growth based on environmental pollution implemented in developed countries over the past 300 years is not feasible in China, and China can not afford the losses brought by this development mode," said China's Minister of Environmental Protection, Zhou Shengxian, at an ongoing theme forum of the Shanghai World Expo in Nanjing, capital of east China's Jiangsu Province. The two-day forum ended Sunday.

China should base its development on its own situation and explore a new development path that is more efficient and sustainable, costs less, and results in less carbon emissions, Zhou said.

After the outbreak of the international financial crisis in September 2008, the world economy suffered the greatest challenge since the Great Depression as the United Nations Environment Programme (UNEP) advocated the development of a "green economy" worldwide.

In China's 4-trillion-yuan (about 588.24 billion U.S. dollars) economic stimulus plan, funds for energy savings, carbon reductions and ecological construction reached 210 billion yuan. Plus the 370 billion yuan in funds used for innovation, restructuring and coping with climate change, "green investment" accounted for 14.5 percent of the stimulus plan. It indicates the government is shifting its values from traditional "profit maximization" to "welfare maximization."

Zhang Guobao, director of the National Energy Administration, said "the government puts great stock in seeking harmonious development between cities and the environment, and is readjusting the energy structure by giving priority to the development of clean and low-carbon energies, including hydroelectric, nuclear, wind and solar power."

Authorities have closed small, coal-fired plants totaling 60.06 million kilowatts in capacity between 2006 to 2009. This year's target of closing 10 million kilowatts of capacity should be achieved by August, he said.

"We have promised to the international community that 15 percent of our power will be generated from non-fossil sources by 2020," Zhang said. At present, non-fossil energy accounted for around 7.8 percent.

The country's operating hydropower capacity in 2009 reached 197 million kilowatts, the highest in the world. Further, the installed capacity of wind power has been doubling every year for the past four years to more than 22 million kilowatts, the third highest in the world, and the figure is expected to exceed 30 million kilowatts in 2010.

Zhang proposed increasing the proportion of clean energy in the total national energy consumption. Statistics show that China invested 34.6 billion U.S. dollars in clean energy in 2009, exceeding the United States which invested 18.6 billion U.S. dollars, to become the highest in the world. However, China's investment in clean energy was only 2.5 billion U.S. dollars five years ago.

China has reduced the traditional high-energy consumption industries while increasing its investment in clean energy. From 2006 to 2009, China shut down 6.06 million kilowatts of small coal fired power units, a figure equivalent to the fully installed capacity of Britain, therefore saving 64 million tonnes of coal and preventing 160 tonnes of carbon dioxide from being introduced into the air every year.

"China took only 30 years to have the environmental problems that had gradually emerged in developed countries over 200 to 300 years. As a big developing country with a population of 1.3 billion people, China is under unprecedented pressure for both economic development and environmental protection," said Minister Zhou Shengxian.

The Shanghai World Expo well illustrates China's effort to save energy and curb carbon dioxide emission. More than 80 percent of the pavilions adopted environmental friendly designs in buildings, while more than half of the pavilions use clean and renewable energy.

However, China's carbon emission reduction target cannot be achieved easily. Wang Ke, a team member of the energy and ecological economy project under the People's University in Beijing, said the shift to a low-carbon economy will only be met at a huge cost to society.

For instance, more than 400,000 people were laid off as a result of the shutdown of small coal-fired power plants from 2006 to 2009. Many studies indicate that curbing greenhouse gas emissions may delay China's development, affect people's income, lead to unemployment and further increase the burden on vulnerable groups in the short term.

Hu Angang, director of the Center for China Studies, a top think tank for policy-making under the Chinese Academy of Sciences and Tsinghua University, said China's promise of curbing carbon emissions and saving energy is not only a response to international pressure, but to meet the internal demands of the transformation of the economic development mode.