When the most recent meeting of the Intergovernmental Panel on Climate Change (IPCC), held in Addis Ababa, ended earlier this month, its conclusion drew negative media headlines. The United Nations body — the world’s forum for climate scientists — had failed, not for the first time, to agree a timetable for its next comprehensive review of the science of global climate change.
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Many countries would like the review, known as the Seventh Assessment Report (AR7), to be published in 2028. This would be in time for a UN climate meeting called the Global Stocktake, at which countries assess their progress towards meeting climate pledges. A number of nations, including some European countries and small island states, want the report to be published ahead of the stocktake. This would allow decisions such as adjustments to pledges to be informed by the latest science.
A second, smaller group, including India, Iran, Kenya, Russia and Saudi Arabia, is arguing that 2028 is too soon. They say that some of the poorest countries lack the capacity to participate in the process of reviewing the report before it is published. They also object to the fact that the studies under review are dominated by science from institutions in high-income countries. However, for AR7, the IPCC says 51% of authors and review editors are from developing countries and nations with economies in transition.
Reviewing IPCC assessment reports is a big undertaking. When AR6 was published in 2023, it ran to more than 7,500 pages and received some 200,000 comments from reviewers around the world.
But the IPCC faces an even more serious problem: it is running out of money. For the first time in its history, it might not have the funds to finish an assessment report. The body relies on voluntary donations from governments and other UN agencies, and these have been falling since 2023 (see ‘Lack of trust’). The funds are also used to support scientists from the poorest countries, allowing them to attend meetings. Many of the countries that want to delay the next report have contributed nothing to the IPCC in years, if ever, although Russia is a notable exception. If contributions continue at current levels, by the end of 2028 the IPCC will be left with just 5 million Swiss francs (US$6 million) — the amount needed for an orderly wind-down of the body.
But there is a way forwards. The IPCC needs more than 20 million Swiss francs to stay operational until the end of 2029, and to complete AR7. Nations must consider increasing their contributions immediately. Other donors, including philanthropists and non-governmental organizations, should also approach the IPCC to see how they can help.
There are those who question whether the world still needs the IPCC. They say that there are faster ways to synthesize climate research, and that much is already known about climate change, its impacts and the measures needed to prevent dangerous consequences. Last week, a separate UN report confirmed that countries are not on track to limit global warming to within 1.5 °C of pre-industrial levels.
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But these arguments overlook the true value of the IPCC, which includes its processes. IPCC reports are produced in a highly consultative way — scientists from the richest to the poorest countries collaborate, ensuring that voices from around the world are heard. This global, scientist-led process also ensures that the quality of the evidence under review takes precedence over political considerations. Once the scientists agree on the main text, governments are involved in writing the summary report, and can choose whether and how to act on the findings. But they cannot change the main text of the assessment report.
The IPCC has survived crises before. One of the most serious was in 1995, when AR2 concluded that “the balance of the evidence” suggested humans are responsible for global warming. This was challenged by representatives of some fossil-fuel-producing countries and oil and gas companies. But the organization’s scientists stood firm, often at great personal cost. Most IPCC-sponsoring governments backed the scientists, and the crisis eventually passed.
The current crisis is more serious because it concerns the IPCC’s very survival. Ideally, governments would come together again and ensure that the organization is properly funded. One way to resolve the matter would be to replace the current process of ad hoc voluntary contributions with multi-year budgetary commitments, similarly to those used to fund many other UN agencies. Support from non-governmental sources should also be considered.
The timing of the next assessment report must be resolved. But the dispute must not be allowed to distract from the most important matter of all: ensuring the continued survival of the IPCC itself.