Eliminating contrails from flying could be incredibly cheap

Summary

Eliminating CO2 emissions from flying is going to be expensive, regardless of the solution the world adopts.But aviation also contributes to global warming through its non-CO2 effects. Those are mostly “contrails”, which I’ll explain in more detail soon. Getting rid of those could be incredibly cheap. So cheap that it’s difficult to understand why we don’t just go ahead and fix it.On a recent podcast, I spoke to Ian McKay, CEO of Orca Sciences, about this. One of their portfolio projects is Contrails.org. Their solution to eliminating contrails is to accurately forecast and model the atmospheric conditions that generate them, and reroute planes so that they avoid these “contrail-forming” parts of the atmosphere.This is a solution that I hadn’t really paid much attention to, and most people are unaware of. So I thought I’d do a deep dive on contrails; explore how this solution might work; and whether it’s really that cheap.To pre-empt the critics: this solution does not mean the aviation industry can ignore the CO2 impacts of flying. Tackling contrails would not absolve them of responsibility for finding low-carbon alternatives to jet fuel. It’s not a substitute, but an addition. Currently, their non-CO2 impacts are not measured or reported, so bringing more attention to contrails means they’re taking full responsibility for their climate impact, which is not the case at the moment.When you see a plane in the sky, you might see a small, white cloud-like trail behind it. Those are contrails (short for “condensation trails”).Water vapour, soot and other particles (basically pollutants) are emitted from the back of jet engines. Water droplets can condense around these particles, and because it’s pretty cold up there, they can freeze to form ice crystals. Sometimes these white lines are very faint and hard to see. But in some cases, they can form “cirrus clouds”: wispy ones that form at high altitudes.These contrails can have both cooling and warming impacts. I’ve sketch...