Climate change and aviation

Aviation has a growing impact on climate change, as demand for air travel increases globally. This POSTnote examines options for mitigating greenhouse gas (GHG) emissions from aviation, including new technologies, demand reduction and emissions offsetting. It also outlines UK and global policy frameworks for implementing measures to do so. 

Key points 

• Aviation is responsible for 7% of the UK’s greenhouse gas (GHG) emissions. 
• Reducing aviation emissions is difficult, because of the long lifetime of aircraft and a lack of zero-carbon alternatives. 
• Technologies which could reduce emissions include new aircraft and engines, electric aircraft and alternative (low-carbon) fuels. They will not bring emissions to zero, and further mitigation will be required. 
• Low-carbon aviation fuels are perceived as promising solutions by the industry. 
• Reducing demand for flying faces social and political acceptance challenges. 
• Emissions offsetting is a key but highly debated approach to mitigating emissions. 
• Aviation policy is agreed globally, but the UK can reduce its own emissions through domestic policy. 

Burning jet fuel releases carbon dioxide (CO2) and non-CO2 emissions. Commercial flights departing from the UK account for 7% of national GHG emissions. Aviation is likely to be the largest contributor to UK emissions in 2050.  

Aviation is the most difficult transport mode to reduce emissions from. There are a wide range of technologies that help reduce emissions. Many technologies lack the required investment under current policies. The coordination of reducing aviation emissions is managed by the International Civil Aviation Organisation (ICAO). Other emissions reduction measures are implemented by the EU. The UK’s has committed to ‘net zero’ emissions by 2050, but the UK Government has yet to clarify how emissions for air travel will be accounted for.  

The Committee on Climate Change (CCC, an independent body that advises the UK government on climate issues) and others have suggested that the UK increase efforts to mitigate emissions from aviation. There are several approaches to doing so, including new technologies, more efficient operations, demand reduction and emissions offsetting. 

Acknowledgements: 

POSTnotes are based on literature reviews and interviews with a range of stakeholders, and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including: 

• ADS Group*
• Dr Simon Weeks, Aerospace Technology Institute*
• Sarabpal Singh Bhatia, Airbus
• Aviation Environment Federation*
• Boeing
• Leigh Hudson, British Airways
• Carbon Engineering
• Dr Stuart Capstick, Centre for Climate Change and Social Transformation, Cardiff University*
• Steve Westlake, Cardiff University*
• Civil Aviation Authority
• Owen Bellamy , Committee on Climate Change*
• Prof. Ian Poll, Cranfield University
• Department for Business, Energy and Industrial Strategy – Aerospace division
• Department for Business, Energy and Industrial Strategy – Emissions Trading division
• Department for Transport*
• Government Office for Science
• Greenpeace
• Dr. John Andresen, Heriot-Watt University
• Prof. Mercedes Maroto-Valer, Heriot-Watt University
• Dr. Bing Xu, Heriot-Watt University
• Prof. Peter Bearman, Department of Aeronautics, Imperial College London
• Prof. Emile Greenhalgh, Composites Centre, Imperial College London*
• Dr Marc Stettler, Centre for Transport Studies, Imperial College London*
• International Air Transport Association
• Jonathon Counsell, International Airlines Group
• Dr. Dan Rutherford, International Council on Clean Transportation*
• International Emissions Trading Association
• Prof. David Lee, Centre for Aviation, Transport and the Environment, Manchester Metropolitan University*
• Natural Resources Canada
• Leo Murray, Possible*
• Robert Thomson, Roland Berger Ltd*
• Rolls-Royce*
• Dr John Green, Royal Aeronautical Society
• Dr Matt Watson, Sheffield University
• Dr Andy Jefferson, Sustainable Aviation
• Bill Hemmings, Transport & Environment
• UK Research and Innovation Future Flight Challenge*
• Prof. Andreas Schafer, Energy Institute, University College London
• Dr Simon Blakey, Department of Mechanical Engineering, University of Birmingham
• Prof. Piers Forster, Priestley International Centre for Climate, University of Leeds*
• Prof. Alice Larkin, Department of Mechanical, Aerospace & Civil Engineering, University of Manchester*
• Dr Emma Harvey, Virgin Atlantic and Virgin Holidays

(* denotes contributors who externally reviewed the POSTnote)