Much of the debate among negotiators from 120 nations had focused on the report's summary for policy makers, effectively a guideline for government action.
"What you see here this week is wrangling over text, over whether something is likely or very likely, whether it is global or regional"
Hans Verolme, World Wildlife Fund
The main bone of contention on Thursday was about what to include on the charts that summarised "key vulnerabilities" of global warming.
Data on the "highway to extinction" charts showed the deteriorating conditions in much of the world, particularly in poorer countries, with every degree of warming.
"What you see here this week is wrangling over text, over whether something is likely or very likely, whether it is global or regional," said Hans Verolme, director of World Wildlife Fund's global climate change program.
"The more urgent the IPCC report is, the higher the public expectations are of the politicians, who this year will have to make a very firm decision to start new negotiations, binding negotiations, for further deep reductions in carbon pollution."
One delegate told the AFP news agency that while European members of the panel sought to include stronger language and hard statistics about the dangers of global warming, the US preferred general statements instead.
"The Europeans want to send a strong signal. The US does not want as much quantification," he said.
According to leaked details of the IPCC, the body of the document reportedly predicts that damage to weather systems from greenhouse gases will change rainfall patterns, lead to more powerful storms, increase the risk of drought, flooding and stress on water resources, and accelerate glacier meltdowns and ice sheets.
Scientists drafting the report predict that "roughly 20-30 per cent of species are likely to be at high risk of irreversible extinction" if global average temperatures rises by 2-3 degrees Celcius.
"By 2080, it is likely that 1.1 to 3.2 bn people will be experiencing water scarcity," a draft of the report's summary said.
The first report by the IPCC in February laid out the scientific case for how global warming is happening, while the second, due to be released in Brussels on Friday, will try to explain what the effects could be.