Heathrow expansion puts Jet Zero at risk

After two decades of dithering, Heathrow Airport finally has approval for its third runway. This expansion, along with approval for improvements at both Gatwick and Luton airports, comes as part of the government’s new ‘growth above all’ mentality. Yet, this mentality has put the government on a collision course with its own – legally binding – climate targets, as well as Sadiq Khan, the figurehead for south-west London’s increasingly disgruntled residents.

Heathrow expansion has long been a contentious topic in British politics. The third runway has twice been given the go-ahead; first under Brown in 2009, and then under May in 2018. But since then, the project has been bogged down in years of litigation over environmental impact and greenhouse gas emissions.

The rise in emissions from expanding Heathrow would be profound. Modelling by the Airports Commission estimates that a third runway would emit 4.4 million additional tonnes of CO2 every year – equivalent to 1.1% of the UK’s 2023 carbon emissions. Although the UK has made admirable progress in complying with its carbon budgets to date and is already near its 2030 aviation emissions target of 35.4 Mt, a new runway at Heathrow would jeopardise the progress that has already been made.

The government has accepted this tradeoff, however, and insists that requiring that 10% of jet fuel be sustainable avation fuel (SAF) by 2030 will offset the extra emissions. However, emissions reductions from SAFs are controversial, as they largely depend on accounting methods for the waste and energy used.

Many obstacles to widespread SAF use remain – notably, production is far below what is needed, and the price of inputs for SAFs remains highly volatile. The government’s promise of a revenue certainty mechanism to encourage and de-risk investment in UK plants for fuel production will no doubt help.

However, more needs to be done. Carbon credits, which are now compulsory for airlines to purchase, are currently cheaper than SAFs. As such, carriers are likely to do the bare minimum to be in regulatory compliance. Raising the price of carbon credits or harsher penalties for non-compliance could boost SAF demand and accelerate their rate of adoption.

Even if optimistic estimates of a 70% emissions reduction from SAFs turn out to be true, the 2030 blending mandate is only 10% – delivering a net emissions reduction of 7%. This would instantly be absorbed by the rise in passenger traffic at Heathrow, not to mention the planned expansions at all four other London airports.

Yet the bulk of the local opposition to Heathrow expansion has not been over carbon emissions, but noise and air pollution. Several west London boroughs under Heathrow flight paths have long lobbied against any increase to flight traffic, citing disturbance due to noise. Recent studies by the WHO have shown that noise pollution is a real health issue, leading to an increased risk of heart attacks, strokes, anxiety and depression.

The UN naming London one of the noisiest cities in Europe has given fuel to these arguments. Blaming aviation alone would be a mistake – road traffic constitutes the overwhelming majority of noise pollution. Residents are simply more accustomed to it and thus do not complain. The areas of London affected also remain markedly quieter than other major cities such as New York and Paris.

This is not helped by London suffering from exceptionally old housing stock, especially in boroughs under Heathrow flight paths. There has been insufficient construction since the 70s: as such, these dwellings have generally poor sound insulation. At the same time, many of these south-west London areas are hotbeds of Nimbyism, hindering the sorely-needed renewal of the housing stock.

Expansion flies directly in the face of the UK’s climate targets and of the Climate Change Committee, which recommends no airport expansion to stay on track to net zero emissions

Heathrow, however, maintains that they can reduce the number of people affected by noise pollution even with a third runway. This would be achieved through a combination of new technology, steeper aircraft takeoff and modified flight paths. The Aviation Environment Federation disagrees – its modelling shows 300,000 people newly affected by flights.

Sadiq Khan’s opposition to the process over air pollution concerns, meanwhile, is wholly consistent with his programme as mayor. Khan has always prioritised air quality, dedicating a major portion of his book, Breathe, to the subject, as well as risking significant electoral backlash over ULEZ. London’s improvement in air quality is notable, and the Heathrow expansion risks undoing the progress made.

There are concerns that a third runway will expose Londoners to more ultra-fine pollution particles, but the Airports Commission has placed limited weight on the suggestion that air pollution will be an issue. Most of the added pollution is projected to come from road traffic leading to the airport, not aviation, an issue that could be addressed using better transport links.

Legitimate concerns over noise and air pollution should not be ignored, but the real environmental impacts is of carbon emissions. Expansion flies directly in the face of the UK’s climate targets and of the Climate Change Committee, which recommends no airport expansion to stay on track to net zero emissions. Given that the government has signalled it will not budge on this, carbon savings will have to be found elsewhere.