BERLIN: After racing against the clock in an all-night session, the UN’s expert panel on climate change was putting the final touches Saturday on a scientific guide to help governments, industries and regular people take action to stop global warming from reaching dangerous levels.

As always when the Intergovernmental Panel on Climate Change adopts one of its high-profile reports, the weeklong talks in Berlin were slowed by wrangling between scientists and governments over which words, charts and tables to use in the roughly 30-page summary of a much bigger scientific report.

The painstaking process is meant to clarify the complex world of climate science to non-scientists but it also reflects the brinksmanship that characterizes international talks on climate action — so far unsuccessful in their goal to stop the rise of man-made carbon emissions blamed for global warming.

“Sometimes it’s framed as if what the IPCC does is ‘just the facts, ma’am,’ and that of course is not accurate,” said Steve Rayner, an Oxford scientist who has taken part in three of the IPCC’s previous assessments, but not this one.

“It’s not pure science and it’s not just politics,” but a blend of both, Rayner said.

In Berlin, the politics showed through in a dispute over how to categorize countries in graphs showing the world’s carbon emissions, which are currently growing the fastest in China and other developing countries. Like many scientific studies, the IPCC draft used a breakdown of emissions from low, lower-middle, upper-middle and high income countries.

Some developing countries objected and wanted the graphs to follow the example of UN climate talks and use just two categories — developed and developing — according to three participants who spoke to The Associated Press on condition of anonymity because the IPCC session was closed to the public.