BANGKOK, May 4 (Xinhua) -- A key scientific report on climate change by the Intergovernmental Panel on Climate Change (IPCC) is to be officially launched here Friday, after four days of debate.

    The agreement was reached by over 120 countries' delegates and experts who attended the IPCC Working Group III (WGIII) session started from April 30 in Bangkok, at the last minute with the last-day meeting ended at over 4 a.m. Friday (2100 GMT Thursday).

    The tiring course aims to finalize the third volume of the IPCC Fourth Assessment Report (AR4) "Climate Change 2007: Mitigation", and turn out a 24-page "Summary of Policy Makers" (SPM), which is to be released Friday noon at a press conference after the IPCC concluded its 26th session to officially adopt the report.

    China, which has sent an 18-strong delegation to the meetings, has been very active in voicing its views over some expressions, wording of text, and accountability of some evidence and conclusion in the draft AR4 and SPM report handed out to all countries for review earlier, some delegates and observers of the meetings said.

    The battles are typical to previous IPCC meetings on its assessment reports, which are expected to provide key technological and scientific background information for later policy making on climate change, a UN official attending the meetings as an observer said.

    The Chinese delegation, led by China's Meteorological Administration Deputy Chief Wang Shourong, is comprised of experts and officials from various economic, social, environment, legal sections and key think tanks with regard to almost every issue covered by the IPCC report.

    The voice of China represented the stance of most of the developing countries, Zhou Dadi, a Chinese energy expert and coordinate lead author of the third volume, said.

    As the biggest developing country, China has devoted many efforts in the study of the impact of climate change and thus has the right to voice out its opinions.

    In comparison, the U.S. delegation, who represented a developed country with the biggest green house gas (GHG) emissions but refused to adopt the Kyoto Protocol, has kept a relatively much lower profile.

    "It will be the biggest target to blame if some issues are put on table," said Olav Hohmeyer, a review editor of the AR4 report and energy economics professor at the Flensburg University of Germany.

    "The U.S. wanted to avoid it (reductions in GHG), but it is not avoidable."

    Hohmeyer called for quicker actions to curb the carbon dioxide level, but he conceded that different countries are in different positions to consider the climate change issue, and the meetings and battles have been all about reaching "a fair compromise of different countries' positions".

    Carbon dioxide in the atmosphere is measured in parts per million (ppm), with today's levels close to 400 ppm but increasing rapidly.

    An early draft of the report obtained by Xinhua says that if the world wants to stabilize carbon dioxide in the atmosphere at 640 ppm by 2030, seen as a ceiling it would cost 0.2 percent of average global gross domestic product (GDP).

    The draft of the upcoming report, contributed by the Working Group III (WGIII) of the IPCC, based on IPCC's research in the last six years on the latest development in the mitigation of climate change in various countries, analyze mitigation options, including policy tools like carbon tax and alternative energy like nuclear power, for limiting greenhouse gas emissions so as to undermine impacts of climate change.

    The launch of the finalized report, after being discussed and approved by delegates of governments at the 26th session Plenary of IPCC on Friday, follows the release of the first and second volume, respectively focusing on "Physical Science Basis", and "Impacts, Adaptation and Vulnerability", in February and April this year.

    The First Assessment Report of IPCC in 1990 has led to the adoption of the UN Framework Convention on Climate Change (UNFCCC)in 1992, while the Second Assessment Report, Climate Change 1995, has played an important role towards the adoption of the Kyoto Protocol to the UNFCCC in 1997.