Between urgency and inclusion: Why the IPCC can’t agree on AR7’s timeline

On the surface, the IPCC’s latest meeting ended in a deadlock over AR7’s timeline. But beneath the stalled negotiations, a deeper struggle is brewing—one over scientific equity, representation, and bias in shaping the climate agenda

When the world’s foremost climate science body convened top scientists in Hangzhou, China, to shape the next global report that will guide climate policies at every level, expectations were high for a challenging session— but it turned out to be grueling. The 62nd session of the Intergovernmental Panel on Climate Change (IPCC) began with a packed agenda and deep divisions—hardly a recipe for success. To make matters worse, the US pulled out of the meeting just days before it was to begin. The aim of this meeting was to end an almost two-year deadlock over a crucial decision: the timeline for the IPCC’s Seventh Assessment Cycle (AR7), the latest climate science assessment by the IPCC. With thousands of scientists representing its 195-member nations, the AR7 synthesizes vast amounts of research to inform global, national, and regional climate policies and wields global influence over climate negotiations on tackling climate change. But more than 30 hours past the meeting’s scheduled conclusion, consensus remained out of reach.

This pattern of delayed deadlines and lack of trust has marred the last few IPCC cycles and have exposed deepening tensions between participating countries. The cycles which began in 1990 (when the first report was published) have witnessed differences grow sharper. This impasse reflects a broader crisis within the IPCC, where calls for inclusivity and urgency collide, raising fundamental questions about whose voices shape the world’s most influential climate science—and whether the process itself needs reform.

At the last meeting, some countries, including the EU and Japan pushed for a faster timeline, hoping the report would inform the next Global Stocktake (GST) in 2028 under the United Nations Framework Convention on Climate Change (UNFCCC). The GST is a 5-yearly review that countries have to undertake to assess collective progress towards the goals set in the Paris Agreement. 

But some nations, such as China, India, Saudi Arabia and Kenya resisted, arguing that rushing the process would compromise scientific rigour and limit participation from developing countries already struggling with funding constraints and alleged institutional biases.

The meeting, however, did see some progress. Delegates finalised the outlines for AR7’s three core reports covering climate science, impacts and adaptation, and mitigation, thereby setting the stage for the next assessment cycle.

What is AR7?

Simply put, this report assesses the state of the climate across the world. The current assessment cycle, which officially began in July 2023, involves extensive global collaboration by climate scientists to evaluate the latest research on climate change. These reports, produced every five to seven years, serve as a guide for international climate policies. They collate the most recent scientific data on climate impacts, vulnerabilities, and mitigation strategies. The AR6 cycle spanned nearly eight years, beginning in October 2015 and concluding in July 2023. Following that timeline, the AR7 cycle would logically be expected to wrap up by 2030.

​Authors chosen from across the world are split into different working groups, which then prepare a summary for policymakers (SPM), ahead of the Synthesis report along with the actual assessment report. The last assessment cycle ended last year, and the reports, which were published between 2021 and 2023, provided crucial insights into the state of the global climate crisis and helped shape some critical policy outcomes including the creation of a Loss and Damage Fund at COP27 to assist vulnerable nations.

Some progress made in China

One of the most critical outcomes at the China meeting was the agreement on the outlines for the three Working Group (WG) reports—covering climate science (WG1), impacts and adaptation (WG2), and mitigation (WG3). This is one of the first steps in the AR7 process, as it sets the scope for what will be assessed in the coming years. The approval of these outlines means the author nomination process can now begin, allowing work on AR7 to proceed, even if the timeline remains undecided.

The meeting also comes in a crucial year, which has already been deemed the hottest on record. It has also witnessed devastating wildfires in California, among other extreme weather events. “We need all hands on deck to tackle the escalating climate crisis. That is precisely the power of the IPCC: bringing together diverse voices in a transparent process so decision-makers everywhere have the best possible information to act on,” said Delta Merner, lead scientist, Science Hub for Climate Litigation, Union of Concerned Scientists, who attended the IPCC meeting in Hangzhou.

The outlines of the WG reports were finalised despite the US’ absence, which is a testament to the determination of countries and IPCC scientists to power through despite the huge setback.

“While the US absence wasn’t a dominant discussion point in the room, its impact is undeniable. The most visible loss was Kate’s [Katherine Calvin, NASA’s chief scientist] leadership as WG3 co-chair, but the real gap is the missing Technical Support Unit (TSU) for WG3—an essential team that helps coordinate and shape the report. Without it, there’s a leadership vacuum in one of the IPCC’s most policy-relevant working groups,” said Merner. 

Calvin was set to lead WG3, while former US president Joe Biden had committed roughly $1.5 million annually for the TSU. All of this support vanished overnight after sitting US President Donald Trump’s administration refused to give officials permission to attend the meeting. The TSU contract was also terminated. 

At the meet, delegates reached consensus on most parts of the Carbon Capture, Utilization, and Storage for National Greenhouse Gas Inventories Methodology Report. However, discussions over CO₂ removal from marine environments were heated. This is because Marine Carbon Dioxide Removal (mCDR) techniques—such as ocean alkalinity enhancement, artificial upwelling, and direct ocean capture—are still largely experimental and poorly understood. Their long-term impacts are untested, and hence unknown. It is also difficult to track, verify and measure mCDR. 

“Governments at the IPCC meeting in China were rightly wary of allowing the development of accounting methodologies for dangerous marine carbon removal approaches, because the science simply isn’t there, and the risks are immense. The meeting also made it very clear that solar geoengineering is not mitigation, but an extremely risky and speculative technology, and any assessment must focus on risks and ethics,” said Mary Church, Senior Campaigner, Center for International Environmental Law (CIEL).

Due to these concerns, discussions on Volume 7 of the report, which covers mCDR, were postponed to IPCC-63 to be held later in the year.

Balancing science and politics

“The deadlock over the AR7 timeline reflects a fundamental challenge: balancing the need for policy-relevant science with governments’ ability to thoroughly review and engage with the findings. Many countries argue that aligning the reports with the 2028 Global Stocktake (GST) is essential to ensure the latest science informs international decision-making. Others worry that a shorter timeline will leave them with insufficient time to review the reports—especially for governments with small teams, where the same experts are often tasked with both writing and reviewing,” Merner told CarbonCopy. 

Shreeshan Venkatesh, global policy lead, Climate Action Network (CAN) International, who also attended the IPCC meeting in China, expanded on this concern. He pointed out that while aligning AR7 with the GST could help strengthen political pressure for climate action, it risks deepening existing inequalities in the IPCC process. “A shorter timeline means less time for governments in developing countries to prepare, integrate their scientific literature, and engage their experts in the AR7 cycle. This increases the risk of repeating the asymmetries of previous cycles, where developed countries—backed by stronger technical capacity and a dominant share of published literature—hold an implicit advantage,” said Venkatesh. “For many developing nations, this feels like a Faustian bargain.”

The process of developing the science for assessment is intense and exhaustive and is considered one of the most comprehensive scientific endeavours globally. It typically involves hundreds to thousands of scientists and experts from fields as diverse as climate science, economics, social sciences, and engineering. For each AR, the IPCC draws from a pool of hundreds of Coordinating Lead Authors (CLAs), Lead Authors (LAs), and Contributing Authors (CAs) who draft the report’s chapters. For instance, AR6 had over 700 authors from 90 countries contributing to the three working group reports, resulting in an 8,000​-page report. The draft reports typically go through multiple rounds of peer review with each draft receiving feedback from thousands of expert reviewers and government representatives with a stated aim to ensure accuracy, inclusivity, and transparency. Over 70,000 review comments were submitted by experts and governments​ for the AR6.

Yet, the IPCC process, despite its stated aim to ensure representation for all countries, is still fraught with political complexities because of the involvement of national governments. 

Governments are involved in the vetting and approval of reports and ensuring that they reflect both the scientific findings and align with international climate agreements and national policies. While the involvement of governments ensures that the reports are both scientifically credible and politically actionable, it can also introduce tensions and negotiations that influence the final content.

The inequality problem 

The IPCC still leans heavily toward developed countries—whether it’s in decision-making, the selection of research papers, or author representation. A 2015 study in Nature flagged how Global South authors were underrepresented in IPCC reports. A 2017 analysis found that in AR5, only 31% of authors came from developing nations. That number improved slightly in AR6 (35%), but the gap remains glaring.

The result? Reports that often fail to fully reflect the priorities of the world’s most vulnerable nations and instead reflect the priorities of wealthier nations

Take the issue of funding, for instance. Scientists from developing countries struggle to secure financial support, making it harder for them to contribute to these landmark reports. Attending IPCC meetings isn’t cheap either. For researchers from poorer nations, travel costs alone can be prohibitive, limiting their participation in discussions that directly affect their regions.

These structural barriers have made consensus-building even harder. The long-standing debate over equity, historical responsibility, and whether to prioritise mitigation or adaptation has turned IPCC meetings into battlegrounds. We’re seeing that play out again now. The timeline deadlock? It’s been stuck in limbo since the IPCC meeting in Sofia, Bulgaria, last July.

For years, developing countries have pushed back against what they call “unequal science.

And the divide isn’t just political—it’s about who gets heard. China, India, Saudi Arabia, South Africa, and Kenya are resisting the push for a rushed timeline. At Sofia, India made its stance clear: “Producing the best science needs time, haste leads to shoddy work.” 

Then there’s the issue of what counts as knowledge. Indigenous and traditional knowledge systems are critical for understanding local climate risks and adaptation strategies, yet they’re often sidelined in IPCC reports. Instead, the focus stays on peer-reviewed research—most of which comes from the developed world. 

The issue with IPCC pathways

This story published in CarbonCopy last year asked an important question: “How realistic are the futures described in IPCC’s models? To what extent do they reflect and preserve the principles of equity and rights to development while charting decarbonisation pathways?”

Two studies published recently addressed these inequalities. This paper offered an alternative model. It developed a framework to address energy and climate equity by classifying 134 countries into four development categories based on 13 indicators related to the economy, energy, environment, human development, gender, and demography–a departure from the IPCC’s current geographical classifications. 

Another study analysed 350 scenarios across five Integrated Assessment Models (IAMs) from the IPCC’s Sixth Assessment Report. The authors found that when IPCC pathways for decarbonization favor “least-cost” strategies, they often push land-based solutions like afforestation or bioenergy crops, which place a disproportionate burden on developing regions. And that reforms can make the current system more equitable. 

Searching for consensus 

“The debate about the timeline comes at an interesting juncture for the IPCC. On one hand, confronted with all the deficiencies of AR6 (and other previous cycles), it is under pressure to reform its methods and scope of content to become more inclusive, representative and fair. On the other is the pressure to align with the Paris Agreement timelines for the second GST in 2028. The question is, can you do both?” says Venkatesh. 

Dr Youba Sokona, former IPCC vice-chair, and an eminent voice for the developing world, however, wrote a letter urging for an expedited timeline for the AR7 and said the process needs more refinement. It does not need delays because of the logjam on faster timelines for the next IPCC AR, he wrote. Merner agrees that delaying a decision has only made the burden worse. “The longer this drags on, the more pressure builds on scientists and governments to work within an ever-tighter window. Small island nations, in particular, have voiced the need for both inclusivity and urgency—recognising that if IPCC reports are to inform GST 2, they must be delivered on time. A balanced approach could have been adopting the proposal from Istanbul, which streamlined reports while maintaining scientific rigor.”

Merner is referring to some workable options discussed at the 60th session of the IPCC, held in January 2024 in Istanbul, Turkey. Three workable options were outlined for AR7. There was a “light option” with fewer reports, which would truncate the timeline to 2028, while a “classical option” would most likely see the cycle extend to the end of 2029 or beginning of 2030 (in line with the next round of NDCs).

Science delayed, climate denied? 

With the world on its way to breaching the 1.5°C threshold set by the Paris Agreement, there is a need for a long-term solution to prevent similar logjams for future reports. Is a rethink of the IPCC’s processes the need of the hour? “Science has always been political. What you study, how you study it and how you frame it, all have profound political dimensions. So an intergovernmental panel negotiating science is bound to get politically contested,” says Venkatesh. 

“The process still favors established climate institutions, and while there’s growing recognition of the importance of diverse knowledge systems—like Indigenous knowledge—integrating them meaningfully requires more than just good intentions. It demands a fundamental shift in how we assess and validate knowledge, something the IPCC is still grappling with,” Merner adds. 

If the stalemate over AR7 is any indication, the future of global climate science hinges not only on the quality of research, but also on the ability of institutions like the IPCC to adapt, innovate, and ensure that the voices of those most affected are heard. The next few months will determine whether the IPCC can break free from this gridlock or if the world’s most authoritative climate science body risks losing its relevance at a time when it is needed most.

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Anushka Mohite

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