That's right. When it comes to aviation, it's unlikely the airlines are going to pay more unless there's an incentive to do so. The incentive can be public reputation, and there's certainly a price that you can put on that. However, when you move into the world of carbon taxes and other things, that's probably what's going to drive the market to an extent at some point in time.
On September 20th, 2018. See this statement in context.