The expansion of Heathrow would be an expensive disaster for Britain and the world. Burnham needs to block it | George Monbiot
A third runway at Heathrow would impose massive economic and environmental costs that far outweigh its benefits, according to government analysis, yet ministers continue to support the project. The Department for Transport calculated the construction would cost between £23.4bn and £62.5bn, yet add only 0.03% to 0.05% to GDP—far less than the airport's claimed 0.43%—whilst causing major harm to the health of up to 3 million people. Transport Secretary Andy Burnham has signalled ambivalence, calling the project "contested" and suggesting it is principally a matter for London.
The climate implications are particularly severe. The Climate Change Committee warns that Heathrow's expansion alone would cause more carbon emissions by 2054 than any other sector of the economy. The true heating impact of aviation is substantially underestimated in policy: when accounting for compounds released in the upper atmosphere, flying's warming effect is 517% greater over a 20-year period than CO2 alone. Proposed sustainable aviation fuel solutions—whether biomass-based or synthetic—are equally problematic; biomass would require half of all UK agricultural land, whilst synthetic fuels have massive energy demands.
- Third runway would cost up to £62.5bn yet add minimal GDP growth
- Project would harm 3 million people's health whilst causing massive carbon emissions
- "Sustainable" fuel solutions would either destroy farmland or require vast energy inputs
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Heathrow is London's largest airport and one of Europe's busiest international travel hubs. The government is considering an expansion project that would add a third runway to increase the airport's capacity, a proposal that has been under consideration for several years as a potential way to handle more passengers and boost economic activity.
The expansion plan has become increasingly contentious because of significant disagreements about its true economic and environmental impact. Government analysis found that construction would cost between £23.4bn and £62.5bn, yet would add only a small fraction of GDP growth, which contrasts sharply with claims made by those supporting the expansion. The project would also have significant health implications for millions of people living near the airport.
The expansion raises major environmental and climate concerns. Aviation contributes substantially to greenhouse gas emissions, and environmental assessments suggest the airport's expansion could be a significant source of additional carbon emissions in the coming decades. Proposed solutions such as sustainable aviation fuels—whether created from biomass or through synthetic processes—face substantial practical challenges that may limit their viability.
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The case for
Heathrow's expansion would strengthen Britain's economic competitiveness by improving international connectivity for businesses and consumers, with lower ticket prices through increased capacity and competition. Modern aircraft already emit far less per passenger than older ones, and the project provides time for sustainable aviation fuels and efficiency improvements to mature at scale whilst the UK pursues decarbonisation alongside growth. Construction and operation would generate substantial employment and economic activity, whilst capacity is necessary to compete with continental rivals like France and Germany.
The case against
Government analysis shows the project would cost tens of billions whilst delivering only 0.03-0.05% GDP growth—negligible returns that cannot justify such expenditure. Aviation's true climate impact is vastly understated in policy: accounting for upper-atmosphere compounds, flying's warming effect is 517% greater than CO2 alone, and Heathrow's expansion would generate more emissions than any other economic sector by 2054. Proposed solutions are illusory: sustainable aviation fuels would require half of all UK agricultural land or enormous energy inputs, making genuine decarbonisation impossible at expanded capacity.