COPENHAGEN, Oct. 27, Xinhua - The Intergovernmental Panel on Climate Change (IPCC) opened a meeting here on Monday to finalize the Synthesis Report, the last stage of its Fifth Assessment Report (AR5), which provides policymakers with a comprehensive assessment of the risks of climate change.

The week-long meeting will distil and integrate the findings of the three IPCC Working Groups released over the past 13 months and the results of the two Special Reports brought out in 2011, providing insights by drawing together related information from the various underlying reports, according to a press release by the IPCC.

"The Synthesis Report will provide the road map by which policymakers will hopefully find their way to a global agreement to finally reverse course on climate change," said Rajendra K. Pachauri, Chair of the IPCC.

"It gives us the knowledge to make informed choices, the knowledge to build a brighter, more sustainable future. It enhances our vital understanding of the rationale for action -- and the serious implications for inaction," he told the opening session of the meeting.

During the meeting, delegates from the IPCC member governments, in consultation with the scientists forming the author team that drafted the report, will scrutinize the Summary for Policymakers to ensure it is consistent with the Synthesis Report.

The AR5 is the most comprehensive assessment of climate change yet undertaken.

Pachauri, who as IPCC Chair led the writing of the Synthesis Report, urged policymakers negotiating a climate agreement to base their decisions on science, saying that addressing climate change "is not hopeless."

Pachauri said the report pointed to the solutions and actions required to tackle climate change.

"We still have time to build a better, more sustainable world. We still have time to avoid the most serious impacts of climate change," he said.

The Synthesis Report is due to be released on Nov. 2.

IPCC is the world body for assessing the science related to climate change. Set up in 1988 by the World Meteorological Organization and United Nations Environment Program, IPCC was endorsed by the United Nations General Assembly to provide policymakers with regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation.