Chemtrail spotters rattled by the sight of clouds streaking the sky, sit tight: researchers in Europe are working on eliminating contrails, the high-altitude condensation trails on which the conspiracy theory rests.
A European Union-backed project called PACIFIC is focused on understanding climate-neutral aviation with the goal of minimising non-CO2 emissions from planes. Non-CO2 emissions are made up of water vapour, nitrogen oxides, carbon monoxide and soot, which together create the streaks of clouds in the sky.
These streaks have spawned the well-established chemtrail conspiracy, which is the mistaken belief that contrails are actually chemical or biological agents being sprayed on the public for nefarious purposes. And contrails are a problem when it comes to our world getting hotter.
Contrails made by a plane flying at high altitude.Credit: Getty Images
Just 10 per cent of flights create 80 per cent of planet-warming contrails. They most commonly occur on long-haul flights, which are essential to almost all Australian international travel.
Under certain conditions, contrails form when water vapour, non-CO2 emissions and soot emitted from engines freeze to form streaks of ice crystal clouds.
The streaks run for an average length of 150 kilometres, or about 10 minutes of flying. Most – but not all – contrails warm the atmosphere.
While only 10 to 15 per cent of contrails are persistent, and most of these last only a few hours, “they can exacerbate climate change by trapping heat radiating from the Earth’s surface”, says Airbus.
Understanding more about the specific conditions that create warming contrails is part of the mission of the Particle emissions, Air quality and Climate Impact related to Fuel Composition and Engine Cycle (PACIFIC) consortium. It’s a gathering of 11 European partners organised to advance climate neutral aviation to cut non-CO2 emissions.
The use of sustainable aviation fuels – on which the aviation industry is placing hopes for a more climate-friendly future – has shown they could cut both soot particles and contrail ice crystals. The PACIFIC program will test an “unprecedented range of fuels under controlled conditions” to “help define new fuel specifications aimed at reducing aviation’s climate and air quality impact”.
Airbus, jet engine-maker Rolls-Royce and the Johannes Gutenberg University Mainz in Germany with the University of Helsinki in Finland are among 11 participating organisations.
Cambridge University Regius Professor of Engineering Steven Barrett, who spoke on the subject at the Airbus Summit in Toulouse, France, in March, says eliminating warming contrails is the goal.
“In practice, determining which ones are warming, neutral or the (probably) small number of potentially cooling contrails may be impractical or difficult,” Barrett later told this masthead.
“If that turns out to be the case, the options will be to eliminate all that are practical to eliminate.” Barrett said the airlines could one day establish a rule of thumb about what kind of contrails were worst for the environment (at night, or over certain types of geography).
The study results could also help scientists and air traffic controllers devise a model that helped minimise or eliminate them, he said.
The study is being backed even as Airbus is slowing – but not abandoning – the development of a hydrogen-powered plane. Airbus has spent five years and $US1.7 billion ($2.65 billion) in research into the zero-emissions, hydrogen-powered aircraft with the goal of making aviation cleaner.
An Airbus spokesman said the broader “hydrogen ecosystem” was now at least five to 10 years behind 2020 assumptions. “While we see the timeline for adoption taking longer, we still see hydrogen as a viable new, true zero-emission fuel to power flight,” he said.
One day, onlookers peering up into the sky may see that the white streaking clouds are mysteriously no more. How land-based conspiracy theorists would greet this development cannot be anticipated.
Chris Zappone travelled to the Airbus summit as a guest of Airbus and Qantas.
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