Google has launched a feature that shows a carbon-emissions estimate for almost every flight in its search results, helping users find more sustainable travel options.
So how useful is this figure? Presumably larger planes have larger carbon footprints... and would show higher CO2 figures in Google's search results. Seems bad if you are a carbon conscience traveler. But if those larger planes were 100% full, the CO2 per passenger may be less than that of the planes that show lower figures in Google's search results... then again, who wants to intentionally travel packed in like sardines? So is the utility of these numbers here to find smaller empty planes to travel on? It's certainly not just a matter of larger is worse in terms of the CO2 footprint that is reported. And in the end the CO2 footprint is a matter of headwind and air traffic on the ground and other factors that can't be known at the time you're booking. Are these numbers just some feel good MIPS... meaningless indicators of performance... of today's air travel?
These emissions estimates are flight-specific as well as seat-specific. For instance, newer aircraft are generally less polluting than older aircraft, and emissions increase for premium economy and first-class seats because they take up more space and account for a larger share of total emissions.
OK... but what about all the other factors? How full is the flight? How much headwind? Which airport(s) are en route and how likely are they to keep planes in holding patterns on the ground or in the air?
Also from the blog...
It’s critical that people can find consistent and accurate carbon emissions estimates no matter where they want to research or book their trip.
I'd argue that that this point we have MIPS with regard to the carbon figure of merit that is published. It's useful in that the same assumptions and omissions exist for every aircraft so relatively speaking the information suffers from the same shortcomings regardless of aircraft but there are still factors that should make this figure dynamic... as the plane becomes fuller and burns more fuel en route, the footprint goes up but the footprint per passenger may go down... inquiring minds want to be clear on this. So I think we have a ways to go before I'll be selecting flights based on carbon footprint.
So how useful is this figure? Presumably larger planes have larger carbon footprints... and would show higher CO2 figures in Google's search results. Seems bad if you are a carbon conscience traveler. But if those larger planes were 100% full, the CO2 per passenger may be less than that of the planes that show lower figures in Google's search results... then again, who wants to intentionally travel packed in like sardines? So is the utility of these numbers here to find smaller empty planes to travel on? It's certainly not just a matter of larger is worse in terms of the CO2 footprint that is reported. And in the end the CO2 footprint is a matter of headwind and air traffic on the ground and other factors that can't be known at the time you're booking. Are these numbers just some feel good MIPS... meaningless indicators of performance... of today's air travel?
Kevin, this is provocative! While not an answer to your questions, I do encourage you to check out a blog published by Google about this: https://blog.google/products/travel/find-flights-with-lower-carbon-emissions/
Indeed... From the blog...
These emissions estimates are flight-specific as well as seat-specific. For instance, newer aircraft are generally less polluting than older aircraft, and emissions increase for premium economy and first-class seats because they take up more space and account for a larger share of total emissions.
OK... but what about all the other factors? How full is the flight? How much headwind? Which airport(s) are en route and how likely are they to keep planes in holding patterns on the ground or in the air?
Also from the blog...
It’s critical that people can find consistent and accurate carbon emissions estimates no matter where they want to research or book their trip.
I'd argue that that this point we have MIPS with regard to the carbon figure of merit that is published. It's useful in that the same assumptions and omissions exist for every aircraft so relatively speaking the information suffers from the same shortcomings regardless of aircraft but there are still factors that should make this figure dynamic... as the plane becomes fuller and burns more fuel en route, the footprint goes up but the footprint per passenger may go down... inquiring minds want to be clear on this. So I think we have a ways to go before I'll be selecting flights based on carbon footprint.