🛫 New comprehensive contrail report shines a light on aviation’s lesser known climate effects 🛬
It's time to address the full climate impact of aviation which goes far beyond bringing down the CO2 emisions.
✈ We are incredibly proud 🎉 to share the comprehensive report on contrail management that Blue Lines has been working on with RMI, and a large group of stakeholders (airlines, industry groups, scientific institutions, NGOs, and tech companies) for the past 6+ months.
Most people know that aircraft emit CO2 into the atmosphere, which heats the planet and contributes to human-created climate change. However, what most people do not know is that aircraft are also responsible for so-called non-CO2 effects that could roughly double aviation's climate impact.
Condensation trails—or contrails—are thought to be aviation's biggest non-CO2 effect. These long white trails behind aircraft consist of water vapor from the engine that freezes and sometimes creates large high-altitude ice clouds that trap heat on the surface of Earth.
In a new report from RMI, we explore how contrails can be managed (by avoiding the areas where warming contrails are created) and provide a comprehensive overview for industry stakeholders, policymakers, climate organizations, and anyone else interested in a climate solution that has the potential to address 1-2% of climate change relatively quickly, at very low cost, and without changing our behavior.
Here are some main points of the report:
1.  We point to solutions for reducing the significant uncertainty around contrails' climate impact and enhancing the accuracy of predicting where contrails might appear to be able to fly around those areas.
2. We discuss and establish how low the future cost of contrail avoidance will likely be relative to the climate benefits of avoiding them.
3. We call out the need for scaling up real-life trials (and large-scale simulations) to learn what is needed to avoid contrails at scale, what the practical implications of airline operations are, how contrail avoidance will impact airspace management, etc.
4. Any contrail avoidance should be done in addition to decarbonization - never at the expense of continued efforts to reduce CO2 emissions.
5. There is a need to measure and report non-CO2 to quantify (and/or reward) efforts to reduce contrail warming
6. Overall, it is time to address the entire climate impact of aviation—not just the CO2.
The new contrail report results from a long-term collaboration between multiple aviation stakeholders. These are the contributing and supporting organizations from page 3 of the report:
(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 – is what Blue Lines promotes and wants to see spread worldwide.)
See you soon.
Joachim Majholm,
Blue Lines