Contrails, or aircraft condensation trails, account for two per cent of human-caused climate change. That's because contrails often grow into cirrus clouds, which trap heat in Earth's lower atmosphere and significantly add to global warming.
The good news: they can be cheaply mitigated by simply changing the flying altitude of planes. Scientists just need to know where and when these human-caused cirrus clouds are forming.
With the collective power and reach of the Global Meteor Network (GMN), Western researcher Denis Vida and his collaborators have a plan for tracking contrails that already boasts financial backing from heavy hitters like Google and Breakthrough Energy.
Denis Vida (Chris Kindratsky)
"We have a rare opportunity to establish Canadian leadership in a rapidly emerging field. We will be the first project in the world to perform large-scale ground-based observations of anthropogenic cirrus clouds right at their formation," said Denis Vida, a physics and astronomy professor and leading expert in meteor physics. "If we pull this off, we'll shave off more carbon dioxide (CO₂) than Canada's entire emissions."
Vida founded and now coordinates GMN, a game-changing international collaboration deploying more than 1,400 cameras globally to capture meteor events and now survey aircraft contrails.
For the contrails project, Vida and his collaborators, including physics and astronomy professor Lisa Schielicke, will leverage GMN's existing infrastructure, which provides significant value both in terms of cost and time, as it eliminates the need to establish a similar network from the ground up. The Western team is also working directly with Breakthrough Energy's Contrails.org, a science-led non-profit focused on intelligent route planning for aircraft.
Contrails form in specific regions of the atmosphere that are sufficiently cold and humid. Forecasts, based in part on new GMN data, will predict where airplanes are likely to form warming contrails and enable air traffic controllers to avoid these regions.
"Contrail formation regions are typically less than one kilometre vertically thick, although they can potentially span several hundred kilometres wide, so it would only take a slight altitude adjustment to avoid them. This is why the mitigation costs are so low. The challenge was mapping those contrail regions, but our team can provide a solution," said Vida, a member of Western's Institute for Earth and Space Exploration.
"Collaborating with partners like Contrails.org and Google Research ensures that Western, and Canada as a whole, remain at the forefront of climate innovation and strengthens our leadership in climate science."
Contrails, which often grow into cirrus clouds trapping heat in Earth's lower atmosphere, account for two per cent of human-caused climate change. They form when water vapour from jet engine exhaust, pictured here, condenses and freezes into ice crystals. (Christopher Kindratsky/Western Communications)
World leader in ground-based observation
This project started after Luc Busquin, an experienced captain with Alaska Airlines and founder of ContrailCast, reached out to Vida about using a GMN meteor camera to observe contrails for climate impact research. After a proof of concept was jointly developed, Busquin gave a talk about the initial findings at Google Campus in London, U.K., at a contrail workshop in June 2024.
"The reaction to the project was overwhelmingly positive. The GMN is exactly what the contrail research community was trying to develop for many years, and our approach was well ahead of any other," said Busquin.
GMN cameras are unique as they are very sensitive, monitor the entire sky and collect images tens of times per second, meaning they can track aircraft contrails while continuing to monitor meteors and track satellites.
"Our technology supplanted other approaches, positioning Western as the de facto world leaders in ground-based contrail observations for climate science. And now we are collaborating with all major actors in the field," said Vida.
Revolutionizing aviation climate change
Previous studies estimate that re-routing a small percentage of contrail-producing flights can mitigate most contrail-induced global warming, yet real-time, high-resolution contrail observation data remains scarce. In fact, only an estimated 15 per cent of total international contrails need to be avoided to reduce 80 per cent of warming.
Existing geostationary satellite systems only on average detect contrails 30 minutes after formation, limiting their utility for actionable mitigation strategies. GMN, with its global distribution of calibrated cameras that directly observe contrails as they are created, offers a unique opportunity.
Vida and his team have already developed a beta version of a pipeline that automatically detects contrails using AI image recognition techniques and pairs them to flights.
"Expanding GMN's application to include contrail tracking holds the potential to revolutionize aviation climate mitigation strategies," said Vida. "The data and methodologies developed will inform Canadian and international policymakers, contributing to the development of evidence-based regulations and standards for contrail mitigation."
By the end of the year, Vida and his team will deliver the first open-access dataset linking contrails with flight parameters and atmospheric conditions. This will give air traffic controllers and various other stakeholders relevant information to re-organize the flow of flight patterns and create real change in future aircraft designs and technologies. A wider deployment of the algorithm for real-time contrail detection and reporting is planned for 2026.
"Integrating contrail metrics into Canada's aviation emissions trading schemes alone could set a global benchmark for addressing non-CO₂ climate impacts," said Vida.
