The UK government has recently announced plans to expand Heathrow Airport by building a third runway. Chancellor Rachel Reeves outlined the details of the proposed expansion in a speech to business leaders at the end of January 2025, stating that increasing Heathrow’s capacity would be critical in helping Britain to grow its economy. Heathrow is already the UK’s busiest airport with over 80 million passengers passing through each year. A new runway could increase the number of flights from 480,000 a year to around 720,000 a year (nearly 2,000 a day). However, the plans have been met with strong opposition by many who believe that increasing air travel does not correlate with the UK’s climate change commitments and net zero carbon emissions targets.
This news comes soon after Doncaster Council also announced its plans to use more than £100m of public funds to reopen Doncaster Sheffield Airport. The airport was closed in 2022 after being declared financially unviable following a challenging period after Brexit and the coronavirus pandemic. Renewed interest and campaigning for the airport have led to attractive funding offers that would enable it to become fully functional once again by as early as Spring 2026, with economic growth and job creation being the main incentives for investment. However, there are many who question the sustainability of such plans and exactly how they fit in with the wider goal of having a greener economy.
This issue was addressed by the University of Sheffield Grantham Centre for Sustainable Futures at their Sustainability Symposium in the autumn of 2024. Here, they questioned whether flying can indeed be part of a sustainable future and the extent to which the reopening of Doncaster Sheffield Airport aligns with the United Nations’ Sustainable Development Goals (SDGs). Their Green Watch team investigated and reported on a number of different aspects of air travel expansion.
One key aspect of becoming sustainable is taking urgent action to combat climate change and its impacts (UN SDG Goal 13). Richard Sulley, a senior research fellow at the Grantham Centre, explained in his report that air transport is notoriously difficult to decarbonise. Although the government has said that it is investing in the development of Sustainable Avian Fuels (SAFs), the reality is that its current target is for 2% of jet fuel to be sustainable in 2025, and for this to rise to only 10% by 2030. Scaling this up any further will prove to be a huge challenge. Official figures show that greenhouse gas emissions from UK international aviation in 2023 were 32.9 million tonnes of CO2e, which was 8% of the UK’s total emissions. Airlines often promote schemes to offset carbon emissions by decarbonising elsewhere, such as planting trees. However, the effectiveness of these schemes is not always measurable and may not be enough to outweigh the carbon being emitted.
The drive for airport opening and expansion is also not aligned with the UN SDGs to promote sustainable growth or ensure sustainable consumption patterns (UN SDG Goals 8 & 12). The UK government is keen to push for Heathrow’s third runway, citing that it will create 100,000s of jobs and promote trading and investment from businesses. However, this will come at a cost to the environment including diverting rivers, noise pollution and habitat loss. The reopening of Doncaster Sheffield Airport may not cause quite such a significant level of environmental damage as the airport is already built, but given the huge cost involved, it does raise the question as to whether this is the best investment of public money.
South Yorkshire Mayor Oliver Coppard agrees with the Grantham Centre’s conclusions that, whilst aviation expansion is not currently environmentally sustainable, South Yorkshire and the University of Sheffield could instead have an innovative role at the forefront of the sustainable aviation revolution, carrying out research into clean technology and finding solutions that will enable us to fly more sustainably in the future. This would be more in line with the UK government’s Committee on Climate Change which has advised that the UK should not have any more airport expansion until we can control the carbon emissions currently produced by the aviation industry, and put a framework in place to manage future emissions from additional flights.
The real question then is not one of green versus growth, but rather using the green agenda as an opportunity for sustainable and innovative growth. Expanding and reopening airports may seem like a good idea in the short term and provide an opportunity for an economic boost (although in reality the financial benefits are usually realised by a relatively small number of investors and businesses). However, in the long-term expansion is likely to mean that increasing numbers of flights are taken as flying becomes ever-more accessible, with a growing volume of CO2 emitted into the atmosphere each year. It would be wiser at this stage to invest in the green energy sector and promote economic growth by innovating cleaner technologies and alternative fuels which could then become part of creating the sustainable airports of the future, benefitting both us and the planet.
