If you shift a route to avoid making contrails and end up on a longer or more turbulent route what is the net benefit to the climate? For example if a plane ends up using more fuel on a longer route to avoid a cold area where contrails could be made or ends up on a route with more headwinds or turbulence.

Is this a bit of green washing?

It's an optimization problem which could be solved if impact of contrails could be estimated. Making a long detour unlikely is good choice but if a small route / altitude changes could help - why not?

That’s not deep insight stuff. I promise you these people are more keenly aware of what constitutes an undesirable solution than that.

From TFA:

> Rather than dramatically changing the route of a flight, the trial will mostly involve changing an aircraft's altitude by around 2,000ft.