Environmental impact of proposed Heathrow expansion
In January 2025, the UK government announced that it supported a third runway at Heathrow, and invited proposals by 31 July 2025, aiming for “delivery of an operational third runway by 2035, with applications for planning consent coming forward in time to enable decisions to be made this Parliament”.1
The government also stated that any scheme must be delivered in line with the UK’s legal climate and environmental obligations.2
Proposals were submitted by seven organisations,3 with those from Heathrow Airport Ltd and the Arora Group being shared in public. While the Heathrow Airport proposal is for a ‘full-length’ 3,500m long runway,4 the Arora Group’s proposal is for a shorter 2,800m runway, which would avoid the need to divert the M25 motorway.5
Analysis by Carbon Brief has estimated that a forest twice the size of Greater London would need to be planted in the UK to cancel out the extra emissions from the expansion of Heathrow, Gatwick and Luton airports.6
The Environment Committee will meet tomorrow to explore the environmental impacts of expansion proposals at Heathrow Airport, with a particular focus on noise, air quality and climate targets.
The guests are:
Panel One (14.00 – 15.10)
- Paul Beckford, Policy Director, Heathrow Association for the Control of Aircraft Noise (HACAN)
- Celeste Hicks, Policy Manager, Aviation Environment Federation (AEF)
- Tracey Waltho, Chair, the Council for the Independent Scrutiny of Heathrow Airport (CISHA)
- Christina Calderato, Director of Strategy, Transport for London (TfL)
Panel Two (15. 15 – 16.00)
- Becky Coffin, Communities and Sustainability Director, Heathrow Airport Ltd
- Matt Gorman, Director of Carbon Strategy, Heathrow Airport Ltd
Panel Three (16.05 – 16.30)
- Toby Perkins MP, Chair, House of Commons Environmental Audit Committee
The meeting will take place on Thursday 16 October 2025 from 2pm in the Chamber at City Hall, Kamal Chunchie Way, E16 1ZE.
Media and members of the public are invited to attend.
The meeting can also be viewed LIVE or later via webcast or YouTube.
Follow us @LondonAssembly.
Notes to editors
- UK government Letter to potential promoters of Heathrow expansion Published 30 June 2025
- UK government Transport and growth update: airport expansion and transition to greener aviation
- These are groups that publicly shared the details of their proposals. Heathrow Airport, Our Proposal for Expanding Heathrow, 31 July 2025; The Arora Group Finalises Landmark Heathrow Airport Expansion Proposal. The seven proposals were confirmed by the aviation minister here in September: https://questions-statements.parliament.uk/written-questions/detail/2025-08-29/71261
- BBC news Heathrow Airport's third runway expansion plans to cost £49bn 1 August 2025
- BBC news Hotel tycoon reveals Heathrow runway expansion proposal 31 July 2025
- Carbon Brief Analysis: UK would need forest ‘twice size of London’ to offset new airport expansion
- Leonie Cooper AM, Chair of the Environment Committee, is available for interview.
- London Assembly Research Unit have also produced a publication on London’s Airports to support this meeting
- Find out more about the work of the Environment Committee.
- Read the agenda in full.
- As well as investigating issues that matter to Londoners, the London Assembly acts as a check and a balance on the Mayor.
For more information, please contact Tony Smyth in the Assembly Media Office on 07763 251727 or [email protected]. For out of hours media enquiries please call 020 7983 4000 and ask for the Assembly duty press officer.