> One trans Atlantic flight can burn as much as fuel as typical person would burn on a car Inna year.
Do you have a link on this? I've tried to look up numbers on this multiple times in the past, but reliable numbers have been hard to come by, especially for recent years. The ones I recall said that trans-continental flights in the US use something like 1/5 of a year's worth of car emissions, not a whole year's worth.
and the fact that a Prius does ~40 km/l, a plane flight, per-passenger, does about as well as a single-occupancy vehicle for each passenger travelling the same distance. The environmental trouble really comes from the fact that it is easy to fly long distances. It is ~7400 miles from SFO to Sydney, so a round-trip really does burn about as much gas as a year's worth of single-occupancy automobile driving.
The article states that the person in question flew at least 30,000,000 miles. That is, in carbon terms, assuming a 2017 aircraft, equivalent to driving around the world at least ~1200 times in a single-occupancy vehicle.
I think the 40 km/l is unrealistic -- that's 95 mpg. Your average car is apparently(?) under a quarter of that, 22 mpg [3]. Although I feel like this is probably a low-ball (possibly old) figure? My guess would've been like 30 mpg, but I don't know how much of the population has a new car.
The source I had was [1] which said a plane emits ~0.9 tons of CO2/person/round-trip, whereas the average car emits ~4.6 tons/year [2]. At 1.7 persons/car [3] that's 2.7 tons CO2/person/year. Now interestingly, I can't seem to see a source for the 0.9-ton figure; I do see some other sites [4] that claim a one-way flight of that distance emits 2.8 tons, which is a 6x difference... I'm not sure which one is accurate. But there's another site [5] quoting a similar figure to the 0.9 tons.
So funny enough I'm kinda back where I'm started... not sure what the right figure is to even 5x...
>My guess would've been like 30 mpg, but I don't know how much of the population has a new car. //
I just ditched a 15yo 7 seater (Opel/Vauxhall Zafira) with engine troubles (burning a lot of oil - maybe a piston compression problem; leaking exhaust manifold), and having a roofbox, and it was still doing 34mpg (UK; that's 15km/l) with primarily short journeys.
Newer cars tend to be larger and heavier than older cars, which does not help fuel efficiency.
For the US specifically, https://www.nytimes.com/interactive/2018/04/03/climate/us-fu... says that in 2016 new "cars and light trucks (i.e. SUVs)" in the US average 24.7 mpg. Based on the charts, restricting to just cars gives you something like 36mpg in the US in 2016. Note that the EU number is much higher at ~46mpg, likely due to the cars being on average smaller.
Though I'm not sure what to make of the fact that the charts seem to show both cars _and_ light trucks at above 25mpg for the US in 2016; hard to reconcile that with the 24.7 number.
Also see the note about how SUVs and vans are considered "cars" in the EU but "light trucks" in the US...
Anyway, the upshot is that it's certainly possible to get something that will get you over 40mpg, but the average is below that even for new vehicles, in the US.
Planes are also moving at roughly 10x driving speeds and air resistance is roughly relative to second power of speed. And they climb to 10 km for the trip. At this kind of numbers gut feeling is guaranteed to go wrong.
With so many pointless flights, I can't even wrap my head around his environment foot print.