Chinese Premier Wen Jiabao vowed that the country is determined to deliver notable reduction promise of carbon intensity set recently even though Friday (the final day of two-week UN climate change conference) sees no positive outcomes.

Wen and his colleagues have been working against the clock during the recent days by telephone diplomacy or meetings to move forward the negotiation agenda.

"I know there are still some obstacles ahead but no matter what outcomes this Friday sees, China is determined to achieve its goal of cutting carbon intensity," said Wen during his flight to Copenhagen Wednesday.

When answering China Daily's question on the scientific bases of the country's goal of slashing carbon emission per unit of economic output by 40-45 percent by 2020 from 2005 level, Wen said China's top-level scientists and economists have worked out the goal after long-time research and feasibility studies.

"It has reflected China's reality and experts from eight top-ranking organizations such as Chinese Academy of Social Sciences and Chinese Academy of Sciences have been involved in the relatively long-time efforts," Wen explained.

There are some critics at home and abroad on China's insufficient explanations of the feasibility study process of setting such a notable target.

However, he said China has been faced with mounting challenges in realizing such a notable cut margin. "This is mainly because it is hard to maintain China's economic growth at the same high rates as it did in the last three decades," said Wen, adding that it's relatively easy for a country to slash carbon intensity when the economy on the fast track.

In the past three decades, China's annual economic growth rate has been stood at 9.7 percent on average but many experts said in the coming years, it is tough for China to develop so fast.

At the same time, China's population is increasing and industrialization and urbanization moves are still in the mid-term stage. Some predicated that in the coming one decade, 300 million Chinese, or the whole population of the US, will move to cities.

"So I believe our carbon intensity reduction is still a daunting task," said Wen. "But we will not change the commitment once we made the decision."

Following the US announced its goal of cut greenhouse gas emission by 4 percent by 2020 from 1990 base, China decided to reduce its carbon intensity by 40-45 percent by 2020 from 2005 level.

This is a continuation after Chinese President Hu Jintao announced China's decision of "notable cut" of carbon intensity at the UN climate change summit in New York in September.

China has started to implement energy efficiency target since 2006 by announcing it planned to reduce energy consumption per unit of economic output by 20 percent during 2006-10 period.

The government first mentioned the concept of carbon intensity cut on June 5th, the Environmental Day by saying that China will integrate such reduction goal into its social and economic development programs.

"However, our carbon intensity reduction plans are voluntary and should not be linked with the rich countries' binding targets," said Wen.