The lock hammer was repeatedly pushed back as officials from major countries such as China, Brazil, Saudi Arabia, the United States and the European Union spent the weekend negotiating key phrases in the text.
The report from the UN’s Intergovernmental Panel on Climate Change concludes a series that has processed massive amounts of global warming research since the Paris climate agreement was signed in 2015.
A summary of the report was approved early on Sunday, but agreement on the main text dragged on for several hours, with some observers fearing it would have to be delayed.
The UN plans to publish the report at a press conference on Monday afternoon.
The unusual process of getting countries to sign a scientific report is designed to ensure that governments accept its findings as authoritative advice on which to base their actions.
At the start of the meeting, UN Secretary-General António Guterres called on delegates to provide “cold, hard facts” to get the message across that there is little time left for the world to limit global warming to 1.5 degrees Celsius (2.7 Fahrenheit) compared to pre-industrial times.
Although the average global temperature has already risen by 1.1 degrees Celsius since the 19th century, Guterrres stressed that the target limit of 1.5 degrees remains possible “with rapid and far-reaching reductions in emissions in all sectors of the global economy”.
Observers said the IPCC meetings have become increasingly politicized as more is at stake to curb global warming, following the annual UN climate talks that usually take place at the end of the year.
One of the thorniest issues at the current meeting was how to determine which nations are considered vulnerable developing countries, making them eligible for cash from a “loss and damage” fund agreed at the latest UN climate talks in Egypt . Delegates have also battled over numbers that indicate how much greenhouse gas emissions need to be reduced in the coming years and how to factor artificial or natural carbon removal efforts into the equations.
As the country that has emitted the largest amount of carbon dioxide into the atmosphere since industrialization, the United States has strongly resisted the idea of historic responsibility for climate change.
An earlier version of this story corrected an erroneous reference to the United Nations, when it should have been the United States, in the third paragraph.