The IPCC’s Seventh Assessment Report – What Makes It So Pivotal?

At the start of last week, the 65^th Plenary Session of the Intergovernmental Panel on Climate Change (IPCC) commenced in Addis Ababa, Ethiopia. Due to conclude on Friday 16^th October, the meeting’s primary focus was to finalise the timeline for the Seventh Assessment Report (AR7), which delivers the IPCC’s core scientific updates used to shape global climate policy. Amidst prevailing uncertainties of whether to fast-track the report for a 2028 release or extend the timeline into 2029, the meeting represented a critical juncture for global climate action. The plenary was tasked with determining whether the report would be published in time for the Global Stocktake – the next global assessment of countries’ progress against the legally binding Paris Agreement targets. If AR7 reports are published too late, the next Global Stocktake will be drawing on the Sixth Assessment Report (AR6), whose core science still holds but whose headline numbers no longer reflect the state of the climate.

However, late on Friday the IPCC announced that the plenary session had been suspended after the meeting overran and many delegations had to leave. The IPCC noted that key agenda items, including the timeline for AR7, “remain open and under discussion”. While no official date has been set, the panel stated that the discussions would resume at the earliest opportunity, extending a period of uncertainty for international climate progress.

What is the IPCC?

Formed in 1988 by the World Meteorological Organization and the United Nations Environment Programme, the IPCC serves as a United Nations body. The organisation regularly reviews the latest climate science and sets out the impacts, risks, and options for adaptation and mitigation.

The IPCC’s scientific assessments are written by leading climate scientists who are divided into three Working Groups with different scopes:

1. Working Group I: The physical science basis of climate change

2. Working Group II: Impacts, adaptation, and vulnerability

3. Working Group III: The mitigation of climate change

Each Working Group contributes to the assessment reports by writing their own section. The published reports help governments at all levels create climate policies and form the foundation for negotiations at UN Climate Change Conferences (i.e., COP). The meeting in Addis Ababa was the next step in this work, setting up the timeline for the AR7 cycle.

The Wider Impact of the IPCC’s Assessment Cycle

The primary point of contention regarding the AR7 schedule involves its alignment with the Global Stocktake. This process requires Paris Agreement signatories to periodically evaluate their collective progress toward limiting warming to well below 2°C (while pursuing 1.5°C), strengthening adaptation, and aligning finance flows with low-emissions, climate-resilient development.

The first Global Stocktake (GST1) was launched in 2021 during COP26 in Glasgow and concluded in 2023 during COP28 in the United Arab Emirates. The IPCC’s AR6 was published in stages between August 2021 and March 2023 and directly fed into the GST1 process, confirming the severe risks of exceeding the 1.5^oC warming threshold outlined in the Paris Agreement and underscoring the urgent need for immediate climate action.

With the second Global Stocktake (GST2) scheduled to run from November 2026 to November 2028, most nations expect AR7 – which formally began in July 2023 – to be finalised in time to inform GST2, ensuring that this process is grounded in the latest scientific evidence. However, several countries have expressed concerns that synchronising the AR7 timeline with GST2 risks compressing the evaluation process, potentially jeopardising the report’s scientific accuracy and overall credibility. The two theoretical scenarios of this situation would mean either:

• Publish AR7 in time for GST2 – ensuring the process is based on the latest science but risking a less comprehensive report due to strict time constraints.

• Delay the publication of AR7 – ensuring the report is as robust and comprehensive as possible, but risking missing the GST2 process entirely and forcing the Stocktake to rely on out-of-date 2021–23 data.

As we overshoot 1.5°C and climate action becomes more urgent, situations of this kind will become increasingly common: decisions will have to be made faster, and be potentially rushed, which is one of the reasons why long-term planning is so urgent in the short term.

The Addis Ababa Meeting

The AR7 timeline debate naturally emerged as the central focus of the 65^th Plenary Session in Addis Ababa, after prior meetings left the timeline issue unresolved. The prolonged decision-making process highlights the complex relationship between scientific assessments and political decisions under the Paris Agreement, which in this instance has become a primary point of contention.

With the Working Groups now having completed the first drafts of their respective contributions to AR7, the plenary had hoped to decide on a path forward. The options under consideration included:

1. Deliver all three Working Group reports by mid-2028: Meets the timeline for GST2 but risks compromising the quality and credibility of the science.

2. Deliver all reports by late-2028: Allows more time to improve report quality but reduces the time available for countries to review the findings before GST2.

3. Deliver Working Group I by mid-2028, and the others by mid-2029: Strikes a compromise by allowing the initial scientific findings to inform GST2 on schedule, while giving the remaining reports enough time to ensure scientific accuracy.

There were concerns that a plenary session ending with no decision would plunge the AR7 cycle into deeper uncertainty, severely damaging the IPCC’s credibility, and its ability to inform policy – and that scenario is now starting to emerge. The IPCC must ensure that discussions are restarted as soon as possible, so that a final decision can be reached. Continued gridlock risks allowing global climate talks to move forward without updated climate science—an outcome the IPCC will seek to avoid in order to protect its long-term value.

Why Membership Organisation Should Care

Membership organisations are uniquely positioned to coordinate sector-wide solutions to help businesses reduce their environmental footprint. When credible, up-to-date climate science is delayed and political decisions are affected, it creates a wave of uncertainty that directly impacts your members' ability to plan for the climate transition.

IPCC-assessed scenarios and emissions pathways underpin many of the framework’s businesses use: science-based target setting, climate scenario analysis in sustainability reporting (particularly for physical risk), and national policy such as the UK Climate Change Committee’s advice on carbon budgets. A new Working Group III report would give these frameworks an updated scientific basis to draw on, so its timing affects when the “science” behind corporate targets is likely to be refreshed.

Additionally, the Working Group I and II reports feed into how organisations assess physical climate risk and plan adaptation, which is increasingly expected in risk disclosures.

The alignment of these reports with the Global Stocktake is crucial for policy predictability. If GST2 is informed by up-to-date climate science, it is more likely drive countries towards stronger national commitments, which in turn shapes the regulatory environment businesses will operate in during the 2030s. Conversely, if GST2 relies on outdated science, its findings may carry less weight, which makes ambitious national targets – and the climate action needed to meet them – far less likely.

Staying ahead of these shifting policy landscapes allows associations to provide the proactive guidance and toolkits their industries need to adapt. Through member meetups, online webinars, and the formation of expert partnerships, Climate Action for Associations (CAFA) helps the membership sector navigate these exact uncertainties, share insights, and effectively guide their respective industries forward. Join CAFA today.