BEIJING, May 21, 2009 (AFP) - China confirmed Thursday that it will demand rich nations cut greenhouse gas emissions by 40 percent from 1990 levels by 2020 in upcoming global climate change negotiations.

In a position paper published for negotiations to be held in Copenhagen in December, China - one of the world's largest emitters of greenhouse gases that cause global warming - did not commit to any legally binding reductions.

"Developed countries shall undertake to reduce their GHG (greenhouse gas) emissions in aggregate by at least 40 percent below their 1990 level by 2020," said the paper, posted on China's planning agency's website.

"Developed countries shall take responsibility for their historical cumulative emissions and current high per capita emissions to change their unsustainable way of life and to substantially reduce their emissions."

The call for a 40-percent cut by rich countries has previously been mentioned in state media, but Thursday's document spells out the demand as official Chinese government policy.

The December negotiations are aimed at hammering out a new climate change pact to replace the Kyoto protocol that expires in 2012.

The European Union has said it would slash emissions by 20 percent by 2020 compared with the 1990 level and raise the target to 30 percent if others set similarly ambitious targets.

State press reports earlier said China was prepared to commit to improved energy efficiency as its contribution to the talks, but such targets were not set out in the position paper.

The energy-guzzling nation pledged four-percent annual cuts in the amount of energy used per unit of gross domestic product from 2006-2010, but so far those targets have been missed.

Developed nations must also ramp up funding for clean energy technology to developing nations, the position paper said.

As a developing nation China under Kyoto did not accept cuts in greenhouse gas emissions, which are blamed for global warming, higher sea levels and other potentially disastrous changes in the climate.

"Fully aware of the seriousness and urgency of climate change and with a deep sense of responsibility for the long-term development of mankind, China is firmly committed to sustainable development," the position paper said.

"In the face of international financial crisis, China remains determined to take unrelenting efforts to address climate change."