eli5: why is taking a plane or helicopter worse for the environment than a train or a boat?
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Planes and helicopters take an enormous amount of fuel to move a relatively small amount of people and cargo. Trains and certain boats use a fraction of the amount of fuel compared to what they can transport, because they’re specifically designed to do so. A plane or helicopter has to use far more because they’re fighting against gravity all the way. And the more fuel you use per person you transport, the worse for the environment it is.
Trains and ships are very fuel efficient relative to the weight of the cargo it carries. Things that fly have to use a lot of energy simply to raise the cargo into the air and then land at the destination. It is basically as simple as that – ships and trains don’t spend energy (ie fuel) to lift the cargo up into the air and therefore can carry huge loads (tens of thousands of tons) per trip.
Because it takes more fuel to move the same distance per passenger mile (miles traveled times number of passengers).
But for an airplane, they need to fly rather fast to maintain enough lift. This greatly increases their drag and therefore increases the amount of fuel they have to use. They also…you know…have to fly UP about 10 miles or so which takes a lot of fuel too. I believe that take-off uses about 10% of the fuel on your average trip, but I’m unable to find more detailed numbers since that percentage will of course go up on shorter flights and down on longer ones.
Trains on the other hand travel a lot slower and are often very long but narrow in the front. This means their drag is much, much lower than a plane even at the same speed. They also roll on steel tracks with steel wheels. This steel-on-steel rolling has very little friction (damn near zero, really) which means they can just glide along those rails with relatively little fuel consumption.
Protip – environmental footprint is pretty much proportional to pricetag as it represents overall labour input required to provide a good or service and that labour has its own environmental footprint which sort of evens out to not depend so much on type of good and service, but on merely the cost.
I mean yeah, plane burns a lot of fuel, but most of the cost is labour – that labor drives cars, heats homes, consumes things, and that all has way more of an environmental footprint that tank of fuel the plane burns directly.
Helicopter ride has more of an environmental footprint than train ride because it plain costs more, drastically so. Plane, well its not so straightforward. For long distances, airplane is cheaper and more environmentally friendly, high speed passenger rail isn’t so cheap and environmentally friendly at all, the infrastructure requirements are absolutely massive. For short distances, rail of course wins out and cargo rail that doesn’t need to be fast also wins out easily over air cargo.
Helicopters, planes in general, are hilariously inefficient. Take a very efficient turbine engine for a helicopter, the Allison 250 now made by Rolls Royce. In cruise it will burn about 28 gallons of Jet-A per hour, and some helicopters have two of them. Step it up a bit and take a Beechcraft King Air 360 and you are burning about 100 gallons of jet a per hour.
In real terms, if your only goal is to move one meatbag from point a to point b, turboshaft engines on flying machines are a good option. The problem is you are only moving 1-13 meatbags on one of these machines. A train or boat can move hundreds of people and cargo.
It is the same reason why a celebrity should just fly first class, yes the 787 burns a massive amount of fuel, but you are also moving hundreds of people and cargo whereas a typical bizjet can move 1-13 people with fuel burns in the 134 gallons an hour range on a good day.
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