China's recently announced carbon intensity target is a notable goal based on sound science, said a Chinese climate expert attending the ongoing UN-led climate talks here.

China has set a domestically binding target to cut the energy intensity per unit of its GDP by around 20 percent from 2005 levels by 2010 in its11th five-year development plan and the National Climate Change Program.

From 2006 to 2008, the energy intensity per unit of GDP was reduced by 10.1 percent, He Jiankun, an energy professor of Tsinghua University, a top university in China, told Xinhua. That meant a total of 750 million tons of carbon dioxide in reduced emissions, he added.

"A reversal of the upward trend in energy intensity during the 11th five-year development period was only made possible by the strong measures China took in energy-saving and emissions reduction," he said.

Adding to the emission control efforts already under way, China last month announced it would reduce the intensity of carbon emissions per unit of its GDP in 2020 by 40 to 45 percent against 2005 levels.

That demands even stronger steps as energy saving and emissions control prove easy at the start and increasingly difficult later on, he said.

In the following years, energy-saving and emissions control will face increasing technological difficulties and entail higher costs, he said.

China's 2020 emissions target leads to increased energy efficiency, and China's total emissions will still rise at a reasonable rate, he said. Such a target will not drag on the pace of economic growth and is based on current national conditions and China's development stage, he added.

Adopting a target different from developed nations' emissions reduction targets reflects the principle of "common but differentiated responsibilities" under the United Nations Framework Convention on Climate Change (UNFCCC).

China's 2020 emissions target is "a voluntary action by China to address climate change and a commitment to the international community," the climate expert said. "It goes beyond the responsibilities (of developing nations) stipulated in the convention."

The convention does not require developing countries to commit to quantified emission reduction targets and asks developed nations to do so.

Under the Kyoto Protocol of the UNFCCC, developed countries have committed to cutting their emissions by an average of 5 percent against 1990 levels over the five-year period ending in 2012.