What's more, Hatoyama's promise was based on the premise that major developing countries participate in emission cuts, which violated the Kyoto Protocol's principle of "common but differentiated responsibilities."

In climate talks, the US and Japan belong to the so-called Umbrella Group which also includes Australia, New Zealand, Russia and Canada.

Umbrella Group countries, which asked major developing countries to accept binding emissions cut, were frequently at odds with the European Union and developing countries.

Australia, for instance, aimed to cut emissions by 5 percent from 2000 levels by 2020, or up to 25 percent if a tough international climate agreement is reached in Copenhagen, and New Zealand pledged to drop emissions by 10-20 percent depending on the final outcome of the Copenhagen talks.

Last month, Russia said it would reduce emissions by 20 percent to 25 percent by 2020 from 1990 levels, but it's worth noting that the country's emissions were 34 percent below 1990 levels in 2007.

Canada promised to curb emissions by 20 percent by 2020 from 2006 levels, which meant only a 2 percent reduction based on the 1990 levels.

As a whole, the developed countries offered only an 8 percent to 14 percent cut below 1990 levels by 2020, according to the latest data from the Climate Action Tracker project run by Ecofys and Climate Analytics for the European Climate Foundation.

The data meant more commitments are needed from the developed countries, as the range of 8 percent to 14 percent is not much above the 5.2 percent reduction required under the first commitment period (2008 to 2012) of the Kyoto Protocol, while lags far behind the 25 percent to 40 percent figure as indicated by scientists for stabilizing climate.

In contrast, more and more developing countries are voluntarily taking steps to curb emissions, although they are exempt from legal obligations under the Kyoto Protocol.

Brazil, three days ago, pledged to cut emissions by 36.1 percent to 38.9 percent from projected 2020 levels. China has also announced that it seeks to reduce the intensity of carbon dioxide emissions per unit of the GDP in 2020 by 40 percent to 45 percent compared with the level of 2005. India followed China by offering a 20 percent to 25 percent slowdown in emissions growth.

The Copenhagen talks are expected to produce a significant agreement on curbing global warming as the world's main emitters start to make efforts.

However, tough negotiations still lie ahead in the upcoming talks to get the developed countries to do more.

(Xinhua News Agency December 7, 2009)