The 13th United Nations Framework Convention on Climate Change (UNFCCC) opened yesterday on the Island of Bali, Indonesia. As Yvo de Boer, executive secretary of the UNFCCC, put it, the principle of "common but differentiated responsibilities" has a major role to play at the conference.

The principle reflects differences on development levels, historical responsibilities and current per capita emissions of various countries. It also represents the consensus of the international community.

Developed countries, in their industrialization and modernization process, were the sources of unrestricted emissions of greenhouse gases, mainly carbon dioxide.

These nations accounted for 95 percent of carbon dioxide emissions worldwide resulting from the use of fossil fuels from the start of the Industrial Revolution in 18th century to 1950, and for 77 percent in the 1950-2000 period.

Continuing the upward trend in recent years, the total greenhouse gas emissions of major industrialized countries reached 18.2 billion tons in 2005, close to the all-time high of 18.7 billion tons set in 1990, as data released by the UNFCCC secretariat show.

Developed countries, therefore, have unshirkable responsibilities for climate change and should fulfill their major obligations.

They should fully meet emissions reduction targets set by the Kyoto Protocol and continue to take the lead in cutting emissions after 2012, when the protocol expires.

For developing countries, as their accumulative emissions in the past and per capita emissions are low, their primary task at present remains economic growth and poverty eradication. To this end, developing countries will have a growing demand for energy, a basic prerequisite for their development.

Therefore, while addressing climate change, the international community should fully consider the developing countries' rights to and potential for development.

At current stage, it is inappropriate to impose compulsory emissions reduction targets on developing countries. These countries, nevertheless, should take actions, in line with their specific conditions, to tackle climate change. They need to pay special attention to introducing advanced clean technologies and adapting them to their own conditions so as to contribute, within their power, to this global endeavor.

The principle of common but differentiated responsibilities also serves as the basis for maintaining and promoting international cooperation. It calls for increasing assistance to developing nations from the international community.

Developed countries should make good on their promises for technology transfer and financial assistance to help developing countries enhance their capacity for mitigation of and adaptation to climate change.

The international community should intensify the research and development of technologies for more efficient use of fossil fuels, for energy conservation, environmental protection, and renewable energies to make these technologies available and affordable to developing countries.

The Clean Development Mechanism set in the Kyoto Protocol promises win-win results: it helps developed countries realize low-cost emissions reduction, and meanwhile promotes sustainable development for developing countries.