Plotting a greener flight path: the CAA publishes revised roadmap for the UK Aviation Environmental Review

On 17 September 2025, the CAA published CAP 3153, announcing its new approach towards the implementation of its environmental reporting obligations through the UK Aviation Environmental Review (the “AER”). The update is timely following the announcement of approval for Gatwick's second runway on 22 September and reflects the CAA's ambition to provide comprehensive, accessible and trusted environmental data for the UK aviation industry. Furthermore, it hints at a higher level of scrutiny in the years to come. 

1. What is the Aviation Environmental Review?

Per Assimilated Regulation (EU) 2018/1139, more commonly known as the Basic Regulation, the CAA is under a legal obligation to publish an AER at least every three years. The last AER was published by the CAA in CAP 2620 in 2023.

The purpose of the AER is to provide “an objective account of the state of environmental protection to civil aviation in the United Kingdom.” In practical terms, this means providing a regular update on a wide range of information covering the relevant period. This includes data on the industry's performance in relation to various environmental metrics, updates on new measures designed to reduce aviation's environmental impact, and recommendations for both the government and industry to consider to drive future improvements.

2. What is the CAA committing to do?

In CAP 3153, the CAA has identified the key areas upon which it intends to focus with future editions of the AER. These are as follows:

• Climate change
• Air quality
• Noise pollution
• Alternative fuels (including SAF) and technological advancements
• Environmental forecasting

In addition to these topics, the CAA is considering including biodiversity and climate change adaptation in future editions of the AER.

The CAA has also identified the tools and metrics it intends to use to report on its areas of focus. These include using the newly developed CAA Emissions Database, which will allow the CAA to report on emissions on a closer to real-time basis. This database is currently under development by the CAA, with more information due to be published in the next edition of the AER, but a consultation held by the CAA in 2024 suggests that it may use certain metrics that will already be familiar to those in the industry, including emissions per passenger kilometre.

The CAA has suggested that it may make more use of the World Health Organization's air quality and noise limits to contextualise its findings on these issues at selected UK airports. This will help the CAA to better understand the environmental performance of those airports internationally. 

Interestingly, the CAA has also indicated that it is considering ways to include new tools within its framework to examine issues such as the impact of contrails on the environment. 

3. What does this mean for airlines?

The data published by the CAA in the previous AER in 2023 was provided on a national level. However, the CAA has now committed to begin disaggregating the data published in future editions of the AER to allow for more effective analysis on a granular level.

This may include publishing data on a “by airport” basis to provide for a better understanding of air and noise quality issues at specific locations. It may also include publishing data showing greenhouse gas emissions caused by aircraft flying to, from and over the UK, as well as data relating to long-haul versus short-haul flights. This will help to provide a clearer picture of how certain sub-sectors within aviation are performing from an environmental standpoint.

Although there is no suggestion that individual airlines, or even aircraft types, will be named in future editions of the AER, this direction of travel suggests a high level of scrutiny for the industry in the future, which may ultimately feed in to higher levels of consumer awareness. Of course, the availability of more accurate and transparent data will also help airlines, as well as other aviation stakeholders (including airports like Gatwick) to plan their operations more effectively to reduce their environmental impact.

4. Conclusion

CAP 3153 represents real progress towards establishing a robust and transparent environmental reporting regime for the UK's aviation industry on a national level. The new roadmap provides for data to be published on a wide range of issues and in a way that promises to be more understandable to the general public and more useable by industry stakeholders. This may prove to be a valuable tool in the journey to Jet Zero.

The enhancements to the AER signposted in this roadmap will drive positive change by assessing and evaluating the effectiveness of Government policy, industry actions and our activities in meeting sustainability targets, alongside highlighting where policy needs to go further.

https://www.caa.co.uk/newsroom/blogs/charting-a-vision-for-environmental-reporting-in-aviation/