The last time the United Nations-backed consortium of climate experts released a special report—Global Warming of 1.5°C in 2018—it set off a swift chain of consequences. Protest movements erupted seemingly overnight. The term “net zero” was suddenly commonplace. Nearly three years later, most of the current momentum behind climate action can be traced back to that report.
The diplomats and scientists who make up the Intergovernmental Panel on Climate Change, as the group is known, are right now meeting by video conference to hammer out their next report, due to be released Monday. It’s a much bigger undertaking, representing a total refresh of the global consensus on climate science for the first time since 2013. For the 234 authors, the process involves synthesizing more than 14,000 studies and, crucially, winning the sign-off of the group’s 195 member countries, any one of which could block key conclusions from appearing in the report’s “summary for policymakers,” the only part most people will read.
That makes it vulnerable to politics—especially the politics of the world’s biggest oil exporters. The IPCC got an object lesson in this risk in 2018, when Saudi Arabia tried at the last minute to defang the 1.5° Celsius report.
When countries signed on to the 2015 Paris Agreement, they pledged to keep warming “well below” 2°C compared to pre-industrial times while also “pursuing efforts” to limit it to 1.5°C. It wasn’t clear what exactly the world would have to do to meet the more ambitious goal. So governments, in the language of diplomacy, “invited” the IPCC to provide an answer.
This was a highly unusual request. The IPCC is an association of volunteer scientists who produce arduous technical assessments, not policy recommendations. The scientists responded by determining that the consequences of 2°C of warming would be significantly worse than those of 1.5°C. Keeping the world at 1.5°C would require that nations halve their emissions of CO₂ by 2030 and eliminate them completely by 2050.
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All of this went into a draft of their report for a meeting of the IPCC scientists and climate diplomats at a summit in Incheon, South Korea, spanning the first week of October 2018. Negotiations followed their usual rhythm—by turns grinding, grandiose and ponderous—under the rising intensity of a ticking clock to the deadline.
With just 24 hours to go, Saudi Arabia brought the production to a halt when it moved to strike language from one of the report’s headline statements. The paragraph in question explicitly called out “nationally determined contributions”—the official name of countries’ climate goals—for not meeting the Paris Agreement’s 1.5°C goal. Saudi negotiators wanted to remove references to national policy statements and the Paris Agreement from the full 616-page report.
The IPCC’s “products must be policy-relevant and policy neutral and not policy-prescriptive,” the Saudi delegation said in an official statement published after the event. The problem, said David Victor, a climate policy expert at the University of California at San Diego, is that the difference between “relevant” and “prescriptive” has never been defined.
“There aren’t clear guardrails for containing objections by countries,” Victor said in an interview this week, particularly when the concern is that the IPCC is blurring the line between informing and influencing policy.