50 Scientists Sign Open Letter Calling for Contrail Action Now
Urge policymakers to take contrail warming seriously by applying several levers
✅ “There is no denying it: we find ourselves in a climate emergency. “This is the first sentence in the open letter signed by 50 aviation and climate scientists released last week during the final days of COP29 in Baku, Azerbaijan, titled “Open letter: Addressing contrails is a no-regrets decision that will help slow climate change.”
As readers of this Substack will know, contrail avoidance is an inexpensive, relatively easy way to eliminate 1-2% of human-induced global warming. Nevertheless, the aviation industry, in general, has not been proactive in dealing with the contrail problem.
“Recognising the impact of non-CO2 effects, particularly contrails, on our warming climate and the urgent need for action, we, aviation and climate scientists, call upon global decision makers to implement solutions to tackle non-CO2 effects of aviation on top of decarbonization efforts,” the letter reads and calls for awareness-raising of the general public on contrails’ climate impact.
The scientists - from all over Europe, including the German Aerospace Center (DLR) and universities like Sorbonne, Cambridge, Oxford, and Imperial College London - also urge policymakers to require companies to report the full climate impact of their business travel while also calling for large-scale contrail avoidance trails. Finally, the scientists ask for “a policy framework, underpinned by a robust monitoring system, to reduce warming contrails and other non-CO2 effects. This will ensure that mitigation measures are quickly adopted, as soon as they are ready.”
Here is the press release from T&E accompanying the letter.
One Day Left! Take Photos of Contrails and Win a Trip to Europe
The E-Contrail project and Breakthrough Energy (contrails) are collaborating to collect more ground observation photos of contrails for research (Deadline is November 24).
Therefore, E-Contrail has launched a competition, which is very simple: Sign up on this webpage, download the contrail observer app (Apple, Android), and take photos with the app of contrails in the sky. That’s all you need to enter the competition and help researchers advance contrail climate science ❤️🔥.
🏆 The prize for the best contrail photo is a trip to “Europe” - the E-Contrail folks have not yet decided where to hold their next meeting - it could be Madrid, Brussels, you name it. This is a great way to help the climate. Thank you! 🙏
Go to Blue Lines’ educational website to explore contrails in depth.
(As regular readers of the Blue Lines newsletter will know, contrails are the wispy white stripes that airplanes sometimes leave behind in the sky (made from water vapor and engine soot). Some of these condensation trails can spread out and become high-altitude ice clouds (cirrus), which reflect some of the sun’s energy back into space but also trap outgoing energy in the atmosphere, resulting in a net heating of our planet equivalent to 1-2% of human-induced global warming. However, we can relatively easily avoid most warming contrails by flying around the contrail-prone areas in the atmosphere. This climate solution – often called contrail management or contrail avoidance – is what Blue Lines promotes and wants to see spread worldwide.)
See you soon.
Joachim Majholm,
Blue Lines