Proposed methodology for the Fourth Climate Change Risk Assessment – Independent Assessment (CCRA4-IA) 

1. Introduction to the UK's Climate Change Risk Assessments

The Climate Change Committee (CCC) has now started the Independent Assessment of Climate Risk that will underpin the UK’s Fourth Climate Change Risk Assessment (CCRA4). This independent assessment will be delivered in 2026 and will provide an updated assessment of the risks and opportunities from climate change and the potential for adaptation to address them. This will be published alongside advice from the CCC to governments around the UK on improving climate resilience in the next round of national adaptation programmes.

This document sets out our intended methodological approach to building the evidence that will underpin CCRA4.

This document is structured in four sections:

• Section 1 introduces the requirements for a Climate Change Risk Assessment (CCRA) under the Climate Change Act (2008), a short summary of current and future projected climate change in the UK, and a summary of progress-to-date on adaptation.
• Section 2 lays out our how we plan to structure the analysis for the CCRA4 Independent Assessment (CCRA4-IA) through the delivery of an updated
• Section 3 lays out our proposed methodology and analytical framing for key aspects of the CCRA4-IA.
• Section 4 lays out our plans for engagement.

1.1 Climate Change Risk Assessment under the Climate Change Act

The UK Climate Change Act (2008) requires that the UK Government must publish a CCRA every five years. The most recent CCRA – CCRA3 – was published in January 2022 and was informed by an independent assessment of the evidence base on UK climate risk and opportunities. The CCRA3 Independent Assessment (CCRA3-IA) was coordinated by the CCC and published in June 2021 together with the required advice on priorities for addressing climate risks highlighted in this evidence base, consistent with the CCC’s statutory obligations under the Climate Change Act.

The CCRA-IA serves as the basis for the UK Government, and the devolved administrations in Scotland, Wales and Northern Ireland, to create National Adaptation Plans (often known as National Adaptation Programmes (NAPs) in the UK), bringing forward actions to address its highlighted risks. A new National Adaptation Programme responding to the CCRA3-IA evidence base was  published by the UK Government in July 2023, and new plans are currently in development in Scotland, Wales and Northern Ireland.

The Fourth UK Climate Change Risk Assessment (CCRA4) is due to be laid in Parliament by the UK Government in January 2027. As with CCRA2 and CCRA3, CCRA4 will be based on an independent assessment (CCRA4-IA) that the CCC will coordinate. This evidence base will be published in 2026. CCRA4-IA will then be used to inform NAPs for the UK and each devolved administration covering five-year periods from the late 2020s to the early 2030s.

1.2 Current and projected levels of climate change

CCRA4-IA will be produced against a background of accelerating climate change and climate-related impacts globally and within the UK.

• The global average surface air temperature has risen by more than 1.2°C above preindustrial levels and is now exceeding the range of temperatures seen over the last 10,000 years.
• 2023 was the warmest year on record globally, reaching very close to 1.5°C above preindustrial levels for the first time across multiple global temperature datasets. Seventy-seven countries set new monthly average records, with large parts of America, Europe and South America experiencing record warm temperatures.
• In the UK, the first ever recorded day with temperatures reaching more than 40^°C was seen in July 2022. The heatwaves across the 2022 summer led to over 4,500 excess deaths in England and Wales, alongside unexpected wildfires and droughts in East Anglia, impacting food production and stressing ecosystems.

Climate risks are increasing. Climate change is making several types of extreme events (including extreme heat and rainfall) more frequent and more intense, and without further adaptation, more impactful to society. Globally, human-induced warming is currently increasing at around 0.25°C per decade. Recent assessments by the IPCC indicate that 1.5°C of human-induced warming above preindustrial levels may be reached in the early 2030s.⁽¹⁾

The latest UN Environment Programme (UNEP) Emissions Gap Report, published in November 2023, highlights the gap between current global emissions reduction ambition and trajectories consistent with the long-term temperature goal of the Paris Agreement (limiting warming to well-below 2°C above preindustrial levels and pursing efforts to limit it below 1.5°C above preindustrial levels).⁽²⁾ Current policies in place around the world put the world on track for a central estimate of 1.8–3.5°C above preindustrial levels by 2100, with uncertainty due to the climate response to greenhouse gas emissions meaning that global average surface temperatures of in excess of 3.5°C by 2100 are still a possibility.  

1.3 Progress on adaptation in the UK

The CCC published a set of adaptation progress reports covering all parts of the UK in 2023 and an independent assessment of the UK’s Third National Adaptation Programme (NAP3) in 2024.^(3,4,5,6,7) These reports have found limited evidence of the implementation of adaptation at the scale needed to fully prepare for climate risks facing the UK. While the recognition of a changing climate within planning and policy is increasing, it is clear that the current approach to adaptation policy is not translating to delivery on the ground and significant policy gaps remain. This is leading to increased risks to society – particularly for the most vulnerable – and potentially costly lock-ins to less-resilient futures.

This limited progress is a direct consequence of the approach in past NAPs. Previous NAPs did not address all the risks from climate change identified in previous CCRAs, have failed to set out a clear ambition for a vision of what being ‘well-adapted’ means, have suffered from a lack of ambition and did not embed a focus on adaptation delivery across government.

In our recent independent assessment of NAP3, we identified three key priorities that would help address these major issues and ensure that the current and future NAPs can drive action across government, and beyond, more effectively.

• Governance: over multiple iterations of past NAPs around the UK, government has failed to make adaptation a top priority, despite the growing evidence of climate impacts. The NAP process is still not sufficiently well-understood or resourced, particularly in local government. The present approach of coordination of adaptation policy is not working. Effective cross-government collaboration is needed to ensure all parts of government are engaged with adaptation and recognise the challenges that climate impacts can have across multiple sectors at any one time.
• Investment: adaptation in the UK is insufficiently funded to manage the scale of the climate impacts we will experience. Current NAPs do not effectively tackle the barriers to investment, such as the low perceived urgency of adaptation, lack of clear targets and the limited understanding of adaptation actions. There also remains a limited understanding on the role of spending on adaptation from the private and public sector.
• Monitoring: the CCC cannot fully assess progress without better monitoring and collection of data to help evaluate our Adaptation Monitoring Framework. A system of comprehensive indicators and data collection is vital and can help improve the response to climate impacts right across the UK.

CCRA4-IA will aim to bring new evidence that can help tackle these long-standing barriers to effective adaptation around the UK.