As part of Chancellor Rachel Reeves’ prioritisation of economic growth, the Government may give the go-ahead to expanding three of London’s airports. But the growth Reeves hopes to achieve would undoubtedly be at the expense of climate and nature goals while likely exacerbating regional inequality – cause to think twice, writes Daisy Jameson. 

For a government with growth its sole priority, permitting airport expansion makes sense. Even with doubt over the growth impacts of air travel that have been presented recently, the gamble might be worth it. Air travel contributed £22 billion to the UK’s GDP and over one million jobs are directly or indirectly supported by it. Private investors will be attracted to the proposition – increasing investment without the Treasury having to spend a penny – and there is a chance that additional capacity might increase tourism and business travel, both of which will contribute to increasing the UK’s GDP.

The Department for Transport projects a third Heathrow runway opening in 2030 would allow the number of Air Transport Movements (ATMs) to increase to 740,000 annually, adding 260,000 to the current 480,000. With expansion, Gatwick Airport’s capacity is projected to increase from 291,000 ATMs in 2019 to 346,000 by 2030 and Luton’s from 160,000 to 210,000. None of the airports included in the Department’s modelling are projected to decline in capacity over the period to 2050. 

However, this government does not, and should not, have just one priority. It is also committed to the legislated target of reaching net zero emissions by 2050; it professes to care about tackling poverty and inequality; and has committed to delivering for nature. The short-sighted decision to approve Heathrow’s controversial third runway, a second at Gatwick, and permitting Luton to double its size will act in opposition to these three ambitions.

Aviation’s contribution to the UK’s emissions – and the threat of stranded assets

Any increase in airport capacity will lead to increased emissions: from more aircraft using the airport, more passengers using ground vehicles to access the airport and additional power use in the airport buildings. These additional emissions will more than offset the savings from reduced aircraft circling. Estimates of the emissions impact of expansion vary. Based on planning application documents, the New Economics Foundation estimates that the cumulative impact of five years of operation of three airport expansions would result in an additional 64 million tonnes of CO2 equivalent if flights were to increase in line with company targets. Transport for London refers to Heathrow Airport Limited’s own analysis that estimates that allowing the expansion of Heathrow airport alone could increase the city’s emissions by 184 million tonnes of CO2 equivalent.

In 2022, emissions from aviation contributed 7% of the UK’s total emissions (36.87 million tonnes of CO2 equivalent). By 2050, with airport expansion included in the baseline, this is projected to rise to over 25% (19.29 million tonnes of CO2equivalent), or 59% of 2019 emissions, over double the proportion of the next highest-contributing sector (agriculture). Progress in decarbonisation is slower relative to other sectors due to uncertainty over how successful the development and rollout of low- and zero-emission aircraft and aviation fuels will be. Best estimates from the Energy Transitions Commission suggest that by 2030, battery-electric and hydrogen aircraft will only just be entering the test phase. Given a commercial aircraft can spend over 30 years in operational service, without widescale scrappage, the planes using the UK’s airports will not be decarbonised by 2050. Sustainable aviation fuel may be commercially available more widely sooner, but its scalability is uncertain, and the fuels still produce CO2 and other non-CO2 emissions.

The UK has been successful in reducing its emissions, primarily through reducing emissions from electricity supply by bringing more renewables into the mix. However, the next few decades of decarbonisation will prove more challenging – and even more so should London’s airports expand. There is minimal space for other sectors to compensate for the increased emissions that these expansions would cause. Before approving any expansion, the Government must set out where it is making alternative emissions savings to counteract the projected increased emissions.

This is not to say that these expansions should never be permitted. It is feasible that decarbonisation of the world’s airline fleet happens sooner than predicted and if this is the case, the UK’s airports will need significant investment to update existing infrastructure to support these new technologies. When it is clear that the technology is safe and scalable, and the Government can be confident about the sector’s decarbonisation and it not increasing emissions, then it will be appropriate timing to be encouraging airport expansion and modernisation. Going ahead sooner could lead to these airports becoming what has been termed ‘stranded assets’ – physical assets that end up having their lifecycles shortened by regulatory requirements to reduce their emissions and competition from more efficient, greener alternatives . 

Do big infrastructure projects really promote local economic growth?

Building new runways has been justified as a way to stimulate the UK economy. One of Labour’s five missions is to “Kickstart economic growth… with good jobs and productivity growth in every part of the country…” What is the true potential of new infrastructure in reaching this objective? 

The IFS Deaton Review of inequality found that differences in infrastructure play a relatively limited role in explaining disparities in income between areas compared with differences in education and skills. The concentration of more educated and higher skilled workers (along with the wage premiums associated with their employment) explains 60–90 per cent of wage disparities between areas in the UK. The review also suggests that the only way for infrastructure to have a substantial impact on spatial disparities in economic performance is if it leads to better local educational outcomes or a relocation of large numbers of skilled workers and the firms that employ them. Given the proposed airport expansions are all in London and surrounding areas of the comparatively wealthy Southeast, this may only succeed in exacerbating these inequalities. 

Where could investment be better placed?

If the Government cannot demonstrate the emissions savings elsewhere in the economy that will allow for an increase in airport expansion, the Chancellor should not permit the expansion of London’s airports. She could instead focus on alternative investments set out by the Energy Transitions Commission that will help the sector decarbonise (including carbon capture capacity for sustainable aviation fuel production or increasing dedicated electrolyser capacity) and could generate growth for the whole UK economy, beyond London and Southeast England, without the same negative impacts as airports. Many green investments have been shown to have broader wellbeing benefits, including cleaner air to UK cities.

In the future, when low-emission air travel is more feasible, the case for airport expansion could be reviewed. 

The author would like to thank Sini Matikainen for her comments and Georgina Kyriacou for editing.