Airlines and airports rejected action to combat global warming caused by jet contrails, which have been shown to account for more than half of the airline industry’s climate impact, new documents show.
Industry argued in government statements that the science is not “robust” enough to justify reduction targets for these non-CO2 emissions2 emissions. Scientists say the climate impact of contrails, or contrails, has been known for more than two decades, with one accusing the industry of a “typical strategy of climate deniers”.
While carbon emissions from jet engines contribute to global warming, research suggests that the contrails that form when water vapor and soot particles form into ice crystals have an even bigger impact. These man-made clouds trap heat in the atmosphere that would otherwise escape into space.
Lobbying on contrails in documents obtained by openDemocracy highlights the lack of consensus among airline executives, scientists and carbon offsetting websites on the exact climate impact of flying. This means that those looking to offset the environmental impact of their flights get significantly different prices.
The Intergovernmental Panel on Climate Change, in a 1999 special report, estimated that aviation’s historical impact on climate was two to four times greater than its CO2 emissions2 emissions alone. A 2020 EU study also reported that non-CO2 Airplane emissions, consisting mostly of contrails, warm the planet about twice as much as carbon dioxide released by planes, but acknowledged there were “significant uncertainties”.
Photo: Rob Matthews/Alamy
Piers Forster, Professor of Climate Physics at the University of Leeds and a member of the Climate Change Committee, which advises the Government on emissions targets, said: “Industry should not hide behind uncertainties and must act to reduce both their carbon emissions and their carbon footprint. reduce emissions quickly2 and non-CO2 Effects.”
Milan Klöwer, a climate scientist at the Massachusetts Institute of Technology, said airlines are following a “typical strategy of climate deniers” by overstating the level of uncertainty about non-CO2 Effects. He said: “Even at their best, they roughly double the effect of CO2 emissions on the climate.”
The airline industry, in contributions to the 2021 government consultation for its “Jet Zero” strategy to achieve net-zero carbon emissions, said more research on non-carbon impacts is needed2 Effects.
Airlines UK, the trade body for UK registered airlines, said: “The science around [non-CO2 impacts] is not yet robust enough to formulate reduction targets.” Ryanair and Wizz Air said it is too early to formulate and implement policies to mitigate the impact of contrails.
Sustainable aviation, which brings together airlines, airports and other industry stakeholders, said there are projects exploring ways to reduce non-carbon emissions2 emissions, but it was still too early to regulate.
It said: “Given the complexity of non-CO2 Impact, the development of science and a wide range of impact, we do not believe that non-CO2 -Emissions should be included in consumer-oriented information.”
When unveiling the Jet Zero strategy last year, the government said sustainable aviation fuel should mitigate the climate impact of contrails.
Airlines tend to ignore non-CO2 Effects in the regulations for offsetting flight emissions. The official tool of the International Civil Aviation Organization for calculating emissions also does not include contrails in its methodology.
BA’s Emissions Calculator says a one-way flight from London Heathrow to New York emits 348kg of CO2E (Carbon Dioxide Equivalent) and charged £3.97 for offset.
But Atmosfair, a German non-profit working to decarbonize flying, calculates that the same trip in a Boeing 777-200, a type of aircraft used by BA, emits 896kg and £18.37 required for compensation. Atmosfair emissions include equivalent CO2 Emissions of 587 kg, mostly due to contrails.
A spokesman for Sustainable Aviation said: “UK aviation recognizes that non-CO2 impacts need to be better understood and addressed, and encourages further research. For this reason we welcomed the inclusion of non-CO2 Monitoring solutions in the EU emissions trading system [and] why trials of aircraft operating on sustainable aviation fuels involve non-CO monitoring2 Advantages.”
Rob Bryher, aviation campaigner at climate charity Possible, said: “These documents show that airlines cannot be relied on to decarbonize on their own. Demand management solutions such as a frequent flyer fee, introducing a fuel tax, carbon pricing or managing airport capacity will be crucial.”
The Department for Transport said: “Our Jet Zero strategy has validated our goal of becoming non-CO2 Aviation impacts by developing our understanding of their impacts and possible solutions and the UK is one of the leading countries working to address this issue.”