A major study on how to limit global warming could be dropped from formal UN climate talks in Bonn this week after a “gentlemen’s agreement” was made under pressure from Saudi Arabia.

Last December four large oil producers, Saudi Arabia, the US, Kuwait and Russia, refused to endorse the influential Intergovernmental Panel on Climate Change (IPCC) report which shows what the world could look like under 1.5C of warming.

The report was commissioned by the UN after the Paris Climate Agreement in 2015.

Now, with UN talks set to continue this week in Germany, Saudi Arabia still objects to the study being part of formal climate negotiations.

The talks are intended to "[raise] ambition to curb greenhouse gas emissions, accelerate resilience-building efforts, and ensure that climate policy is built on a solid foundation of the best available science and knowledge" in the light of the Paris accord, according to the UN.

Penguin habitats threatened by climate change Show all 9 1 /9 Penguin habitats threatened by climate change Penguin habitats threatened by climate change Gentoo penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins in Cuverville Island, designated as an Important Bird Island. These penguins feed on krill but krill is growing scarcer due to climate change AFP/Getty Penguin habitats threatened by climate change Penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins in Cuverville Island, designated as an Important Bird Island. These penguins feed on krill but krill is growing scarcer due to climate change AFP/Getty Penguin habitats threatened by climate change Chinstrap penguins on King George Island. Global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins in Cuverville Island, designated as an Important Bird Island. These penguins feed on krill but krill is growing scarcer due to climate change AFP/Getty Penguin habitats threatened by climate change A penguin and a seal. Global warming has affected the glaciers that these animals live on and has brought new species to compete with AFP/Getty Penguin habitats threatened by climate change Gentoo penguins on Ardley Island, Antarctic, where global warming has affected the glaciers that the penguins live on and has brought new species to compete with AFP/Getty

“If countries are not able to agree on welcoming the report’s findings or doing anything with them, it’s awkward,” Carl Schleussner, head of climate science at the NGO Climate Analytics told Climate Home News.

A “gentlemen’s agreement” was believed to have been made before the meeting, meaning there could not be dedicated space for country representatives to discuss the key findings.

This means that discussions will finish next Wednesday even if no agreement has been reached.

“This is a gentlemen’s deal that is not very gentlemanly,” Jennifer Tollmann, policy advisor at think-tank E3G told Climate Home News.

The IPCC report looked at all available scientific literature and laid out what would happen if the Earth’s average temperature was allowed to increase by 1.5C compared to 2C.

It took more than two years to produce and included the assessment of more than 6,000 scientific studies. The aim was to help those in power to ward off climate change and support sustainable economic development.

Saudia Arabia’s senior negotiator Ayman Shasly has previously told Carbon Brief he does not wish to formally “welcome” the IPCC report.

He said: “You would not say things like, you ‘welcome’ it…because that [means] we are giving legitimacy to some scientific report…that had its own issues of scientific gaps, knowledge gaps,” he said.

He also criticised the report for not giving developing countries more generous carbon allowances.

CO2 emissions must be cut by 45 per cent from 2010 levels by 2030 to curb warming at 1.5C.