A major report, commissioned by environmental justice organization Friends of the Earth and conducted by the Tyndall Centre for Climate Change Research at the University of Manchester, asserts that the expansion of Heathrow Airport cannot proceed without jeopardizing the UK's legally binding climate targets. This analysis is the first detailed examination of how Heathrow's expansion aligns with the UK's carbon budgets, revealing that the aviation sector is already projected to exceed its share of the Seventh Carbon Budget (2038–42) by 21% to 50% even before any Heathrow expansion.
The report critically evaluates the two main technologies relied upon to reconcile aviation growth with carbon budgets: Sustainable Aviation Fuels (SAF) and Greenhouse Gas Removals (GGR). It concludes that neither SAF nor GGR are on track to provide sufficient capacity within the necessary timeframe. Specifically, SAF production faces structural constraints and competes with agriculture for resources, while large-scale GGR facilities are not yet operational in the UK, making the reliance on these unproven technologies to offset future emissions inconsistent with serious climate action. Furthermore, the analysis points out that the government's own modeling indicates an overshoot of the aviation sector's carbon budget.
Key findings include that the UK's aviation sector will exceed its share of the Seventh Carbon Budget by approximately 40% before Heathrow expansion. The report also highlights that non-CO₂ impacts from aviation, such as nitrogen oxides and contrails, which account for about two-thirds of the sector's climate warming, are not fully captured within current carbon budgets and should be incorporated into future targets. The researchers, including Dr. Lois Pennington, Professor Alice Larkin, and Dr. Chris Jones, recommend against any proposed expansion at Heathrow Airport, stating that aviation cannot continue to grow if the sector is to meet its proportionate contribution to the UK's carbon budgets.
The proposed expansion would cost an estimated £33 billion, including £1.5 billion for relocating the M25 motorway, and would increase Heathrow's capacity to 756,000 flights and 150 million passengers annually. Lord Khan expressed deep concern about potential adverse impacts on air quality, noise pollution, the environment, and other transport networks. The Climate Change Committee (CCC), the UK government's climate change advisory panel, stated it has not yet been asked to formally assess the impact of Heathrow expansion on carbon emissions targets but has repeatedly cautioned against airport expansion, noting "limited space for aviation growth" without emissions reductions. The government maintains that any expansion must align with the UK's legally binding net-zero target by 2050 and will engage with the CCC during the assessment process.
