A bit tangential but allow me to share an interesting anecdote. My MSc dissertation was on accounting for aeroplane fuel emission... during research I discover

A bit tangential but allow me to share an interesting anecdote. My MSc dissertation was on accounting for aeroplane fuel emission... during research I discovered an interesting fact; because of how the EU ETS (airline emissions regulations) works, (fuel consumption acts as a proxy for emissions) you can technically end up with less ETS penalty by adding a stop just before entering the EU. You see the penalty applies for the entire flight and not the portion over EU airspace... so you just have to condense the flight instead. So add a stop just before adding EU, and now you have two flights instead of one, and that second flight has lower 'emission' even though the entire trip was longer, and more importantly the extra stops's landing and take off increases fuel expenditure and thus emissions! Gives you some perspective on how legislation to reduce fuel usage and emissions can act counter to its stated goals. ____ > https://docs.lib.purdue.edu/jate/vol2/iss2/3/ > Another way to reduce the EU ETS charges is to change the route so that the last leg of the flight into or out of the EU is shorter than the current non-stop route. Changing routes to include an additional stop reduces the amount of fuel used for flight segments into and out of the EU, and therefore reduces EU ETS charges because the charges are based on fuel consumption during the entire flight, not just the portion over EU. A major US-based cargo carrier, UPS Airlines, considered adding stops to reduce the EU ETS charges (Cameron & Michaels, 2011). Instead of flying non-stop from between hubs in Hong Kong and Cologne, Germany, the route would be changed by adding a stop in Mumbai, India. While UPS estimates that the route change reduces the ETS charge by 25%, UPS also estimates that the emissions are increased by 33% due to the longer route and added takeoff and landing.