The role of the IPCC in climate legislation and litigation
The IPCC is not a legislator, not a regulator and not a research institute. It is an intergovernmental panel that assesses and summarises existing scientific literature. Even so, its reports play a key role in climate legislation and climate litigation. Courts use them to establish facts that would otherwise have to be proved case by case. That role has limits, and those limits have become sharper in recent years.
The short answer
- The IPCC was set up in 1988 by the World Meteorological Organization and the UN Environment Programme.
- It carries out no research of its own but assesses published scientific literature.
- The summaries for policymakers are approved line by line by governments.
- The sixth cycle (AR6) ran from 2021 through to the Synthesis Report of 2023.
- The seventh cycle (AR7) began in 2023; the Synthesis Report is expected by the end of 2029.
- Courts use IPCC reports to establish facts, not as a rule of law.
- The most important limitation: the IPCC provides global scenarios, not obligations for a single state or a single company.
What the IPCC is
The Intergovernmental Panel on Climate Change was established in 1988. Its members are states. The panel has three working groups: on the physical science basis of climate change, on impacts and adaptation, and on mitigation.
Its working method is essential to its legal value. The IPCC takes no measurements of its own and publishes no new studies. It assesses what the scientific literature says and weighs the degree of certainty.
The reports are drafted by hundreds of authors and go through several rounds of comment by experts and governments. The summary for policymakers is then approved sentence by sentence by the participating governments.
The IPCC describes itself as policy-relevant but not policy-prescriptive. It states what the consequences of particular choices are, not which choice a country should make.
What the IPCC is not
Three misunderstandings persist in legal practice.
First, the IPCC is not a treaty body under the Paris Agreement. It stands alongside the international climate framework rather than within it. An IPCC report creates no obligation.
Second, IPCC reports are not standards. The figure of 1.5 degrees comes from the Paris Agreement, not from an IPCC report. The IPCC describes the consequences of 1.5 degrees and the emission pathways that go with it.
Third, the scenarios are not predictions. They are conditional projections based on particular assumptions about policy, technology and the economy.
The reports: AR6 and AR7
The sixth cycle
The sixth assessment cycle produced three special reports. They dealt with warming of 1.5 degrees (2018), with climate change and land (2019) and with the ocean and the cryosphere (2019).
The working group contributions appeared in 2021 and 2022. The overarching Synthesis Report, entitled Climate Change 2023, followed in 2023. AR6 remains the most recent complete assessment at present.
The seventh cycle
The seventh cycle formally began in July 2023. During 2024 and 2025 the outlines of the three working group contributions were agreed and the authors were selected.
Alongside the three working group contributions, three further products are planned: a special report on climate change and cities, a report on short-lived climate forcers and a methodology report on carbon dioxide removal and carbon capture. Those products are expected in 2027. The AR7 Synthesis Report is expected by the end of 2029.
This means that litigation will continue to rely on AR6 for the next few years. Anyone invoking scientific findings should bear in mind that the underlying literature is by now several years old.
How the IPCC is used in legal terms
In legislation and policy
IPCC reports steer the legislative process along two routes. Directly, because they serve as a common factual basis in negotiations under the climate convention. Indirectly, because legislators base their targets on them.
European and Dutch climate targets can be traced back to IPCC findings in that sense. The targets themselves are political choices, however, laid down in regulations and statutes. It is that legal basis, and not the report, that binds.
As a finding of fact in litigation
In proceedings, IPCC reports function above all as evidence of general facts. The court then does not have to establish afresh in every case that warming is caused by human activity. The same goes for the seriousness of its consequences.
That use is not in essence controversial. In the Urgenda case the court relied on the international scientific findings to establish that a real risk existed. The European Court of Human Rights did something comparable in 2024. The International Court of Justice also relied heavily on the IPCC’s findings in its 2025 advisory opinion.
The reports therefore supply the factual underpinning for the standard. They do not supply the standard itself.
The caution this calls for
Precisely because IPCC reports carry weight, precision is needed. Four points deserve attention.
- From global to individual. The IPCC describes global pathways. A reduction obligation for a single state does not follow automatically from those pathways, still less one for a single company. The Hague Court of Appeal dismissed the claim against Shell in 2024 partly because there is no scientific consensus on a reduction percentage for an individual company.
- The language of uncertainty. The IPCC uses fixed terminology for likelihood and confidence. Those words are technically defined. Translating them into more assertive language in a pleading distorts the source.
- The negotiated character of the summary. The summary for policymakers is approved by governments. For a precise submission, the underlying chapter is often the better source.
- Ageing. Years pass between the literature cut-off and publication of a report. More pass between two cycles. In cases about recent developments, additional evidence may be needed.
What this means for your organisation
For companies, the IPCC is mainly relevant as background to two files.
The first is reporting. Under the CSRD and the ESG reporting built on it, you must explain how your strategy relates to a scenario that limits warming. The scientific basis is part of that assessment.
The second is liability. In climate litigation the standard of care is shaped in part by what a company knew or ought to have known. Published IPCC findings count towards the question of what was foreseeable.
Frequently asked questions
Is an IPCC report legally binding?
No. An IPCC report is a scientific assessment with no legal force of its own. What binds are the treaties, regulations and statutes that may build on those findings.
Can I rely on an IPCC report in proceedings?
Yes, as support for the facts. Preferably refer to the underlying chapter and reproduce the language of uncertainty verbatim.
When is the next full report due?
The seventh cycle is under way. The special reports are expected in 2027 and the Synthesis Report by the end of 2029.
Contact
Would you like to know how scientific findings work through into your permits, your reporting or your liability exposure? Our environmental law solicitors advise on environmental law and sustainability law. Law & More has offices in Eindhoven and Amsterdam and works in Dutch and English. Please feel free to contact us.
