The Intergovernmental Panel on Climate Change failed to agree a publication schedule for its next major assessment cycle after its 65th plenary session collapsed in Addis Ababa, Ethiopia, on 16 October. It was the sixth consecutive failure to agree a timeline since 2024, according to the Earth Negotiations Bulletin, which tracks the talks.
IPCC chair Jim Skea suspended the session late in the evening after many delegations, including small and vulnerable countries with limited negotiating teams, had already left because the meeting ran past its scheduled close. Delegates could not agree on either the publication dates for the three working group reports in the panel’s Seventh Assessment Cycle or the associated budget, leaving both questions open for a future session with no fixed date.
Vulnerable nations say the delay has a cost
The Least Developed Countries negotiating group called the outcome deeply disappointing in a statement issued on 21 October. Its chair, Adao Soares Barbosa, said delaying the climate science “represents a betrayal to vulnerable developing countries”. The group warned that further delay could mean the new assessment reports miss the deadline to inform the second Global Stocktake, due in 2028 ahead of the COP33 climate summit, when countries are meant to review collective progress against the Paris Agreement’s goals.
A bloc including Saudi Arabia, India, Russia, Iran, Iraq, Algeria, Syria and Belarus pushed instead for publishing the working group II and III reports in 2029, arguing a shorter deadline would strain government reviewers and scientists and risk weakening the rigour and inclusiveness of the assessment. India specifically objected to characterising the proposed schedule as delayed, noting it was already more compressed than the timelines used for the panel’s fifth and sixth assessment cycles, which each took longer from commissioning to publication than the current proposal demands.
Other countries sought middle ground. Zambia said the 2028 deadline remained achievable if negotiators added safeguards, including a ban on back-to-back government review periods and guaranteed support for scientists from developing countries to take part fully in the review process. Yemen and Tunisia called for a more careful weighing of reviewer workloads before setting any date, stopping short of endorsing either camp outright.
Reports underpin the next decade of climate policy
Skea told delegates the plenary’s business “has not finished” and pledged to reconvene talks “at the earliest opportunity”, though no date has been set. The dispute leaves the IPCC’s seventh assessment cycle, the scientific backbone for climate negotiations through the end of the decade, without a confirmed publication calendar barely weeks before the COP31 climate summit opens in Antalya, Turkey, in November.
The assessment reports function as the main scientific reference point governments use to set emissions targets and adaptation plans, making their timing directly relevant to how quickly countries can act on updated climate data. Developing countries have repeatedly argued that delay disproportionately affects nations with the least capacity to commission their own climate science, leaving them reliant on the IPCC’s periodic reports to understand emerging risks to their own agriculture, water supplies and coastlines.
The standoff adds to a packed international environmental calendar this month, as biodiversity negotiators in Armenia and conservation researchers in India’s north-east separately work through their own gaps between scientific findings and the political will to act on them.
The IPCC’s three working groups cover, respectively, the physical science of climate change, the impacts and adaptation options countries face, and the policies available to cut emissions, together forming the evidence base cited in nearly every national climate plan submitted under the Paris Agreement. A delayed seventh cycle would leave governments negotiating the next round of emissions targets with scientific assessments that are, in places, more than a decade old by the time any replacement arrives, a gap scientists say matters most for fast-changing fields such as regional rainfall projections and sea-level rise.
