BERLIN -- Publication of a major new United Nations report on climate change is being held up by a battle between rich and developing countries over emissions targets and financial aid to vulnerable nations.
The report by hundreds of the world's top scientists was supposed to be approved by government delegations Friday at the end of a weeklong meeting in the Swiss town of Interlaken.
The deadline was repeatedly extended as officials from big nations such as China, Brazil, Saudi Arabia, as well as the United States and the European Union haggled through the weekend over the wording of key phrases in the text.
The report by the United Nations' Intergovernmental Panel on Climate Change is meant to cap a series that digests vasts amounts of research on global warming compiled since the Paris climate accord was agreed in 2015.
A summary of the report was approved early Sunday, but three sources close to the talks have told The Associated Press that there is a risk that agreement on the main text may need to be postponed to a later meeting. They spoke on condition of anonymity due to the confidential nature of the talks.
The unusual process of having countries sign off on a scientific report is intended 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 Antonio Guterres called on delegates to provide " cold, hard facts " to drive home the message that there's little time left for the world to limit global warming to 1.5 degrees Celsius (2.7 Fahrenheit) compared with pre-industrial times.
While average global temperatures have already increased by 1.1 C since the 19th century, Guterrres insisted that the 1.5-degree target limit remains possible "with rapid and deep emissions reductions across all sectors of the global economy."
Observers said the IPCC meetings have increasingly become politicized as the stakes for curbing global warming increase, mirroring the annual UN climate talks that usually take place at the end of the year.
Among the thorniest issues at the current meeting are how to define which nations count as vulnerable developing countries, making them eligible for cash from a 'loss and damage' fund agreed at the last UN climate talks in Egypt. Delegates have also battled over figures stating how much greenhouse gas emissions need to be cut by over the coming years, and how to include artificial or natural carbon removal efforts in the equations.
As the country that has released the biggest amount of carbon dioxide into the atmosphere since industrialization, the United States has pushed back strongly against the notion of historic responsibility for climate change.
