Hyperloop has lofty design goals. Advocates claim it will be as fast or faster than commercial aircraft, more convenient and comfortable than trains and buses, and extremely energy efficient. It will also be environmentally clean, powered with 100% energy from renewable sources. How does this matter in the global picture of greenhouse gas emission? Let’s do a thought experiment to investigate.
The question is this: How much of all global transportation – both people and freight – could be done by hyperloop, and how much less greenhouse gas would be emitted because of it?
For this thought experiment let’s make some grand assumptions. That hyperloop exists today, that it is a fully built-out network comparable to the great highways and motorways of the world, and that it is powered entirely by electricity from renewable sources - wind, solar, hydro, geothermal…but no fossil fuels.
First, some context. According to the International Energy Agency, an international organization that tracks energy use, global CO2 emissions from all sources were about 32 gigatonnes in 2016. That’s a huge number and by the way, tonnes (metric tons) are about 10% larger than U.S. tons.
Global transportation is a major source, around 25% of that total. Emissions from industrial activity and buildings (homes and commercial structures) are too.
Which modes of transport are emitting the most CO2? The chart below, also numbers from IEA, shows us. Worldwide road transportation (both passenger and freight) accounts for nearly three-quarters of the total, with aviation and ship transport producing most of the rest. Digging into the IEA numbers, we find that Rail accounts for 2-3% (it’s part of “Other”), and also that the big road transport category is almost equally divided between freight moved by heavy trucks and passenger travel in cars and light trucks.
Let’s consider how hyperloop could substitute for some modes of travel. Its vision and current design proposes an eco-friendly method for fast regional connectivity, and we expect the greatest emissions benefits from those trips. However, it’s also possibility that variants of hyperloop could improve localized congestion.
Road Travel: People driving cars and light trucks (Passenger Road Travel) make up the largest emission contribution from this mode, closely rivaled by trucking (Road Freight). Musk’s inspiration and goal to cure our highways of “soul-destroying” traffic congestion came while driving his car between LA and San Francisco. But the preponderance of miles driven are local trips –people commuting to work, going to the grocery store or out for a movie. Longer road trips account for only a few percent of personal driving. About 8% of passenger car miles are for trips longer than 100 miles (5% for trips more than 300 miles). On the other hand, according to the IEA about half of CO2 emissions from road freight come from the large highway trucks – all the semis, big-rigs, 18-wheelers that prowl our interstates, with the other half from local deliveries. If hyperloop displaced a large fraction of those 18-wheeler trips, it could make a real dent in global CO2. Those rigs generate around 18% of the entire transportation sector’s emissions. There are other benefits also, in terms of local air quality and road wear-and-tear. One estimate is that a single fully loaded 80,000-pound truck causes more damage to a highway surface than 5,000 cars.
Aviation: Flying is a CO2 intensive form of transportation. One New York Times report says, “Take one round-trip flight between New York and California, and you’ve generated about 20 percent of the greenhouse gases that your car emits over an entire year.” Actually, flying is even worse for our planet than the CO2 numbers suggest. When the gases and particulates in jet exhaust are released high in the atmosphere they react and change the concentrations of methane and ozone, which also affect Earth’s radiation balance. To account for this, climate scientists use a multiplier of at least 2 and sometimes as large as 6 to represent the climate impact of aviation over and above its CO2. Any reduction in aircraft emissions will yield big benefits!
Hyperloop could be a great substitute for many flights, but not transoceanic trips. Recently, Sir Richard Branson, Virgin Group founder and former Chairman of Virgin Hyperloop One, was quoted as saying, “If every passenger trip on earth between 500km and 1,500km currently made on flights was made by a hyperloop, we could reduce yearly emissions [from aviation] by an estimated 58 per cent.” That seems reasonable for the domestic, rather than transoceanic, trips that could instead be made by hyperloop. We checked this against a day of flights in the U.S. and agree. About 60% of the total flight miles are from flights of 300 miles to 1100 miles. If those emissions from aviation were eliminated it would remove another 7% of the transportation sector’s CO2 emissions! Actually, the totals may be even greater since shorter flights often burn more fuel per mile.
Ships: Huge amounts of freight are moved by ships. They account for more than 70% of global freight ton-miles and create only 11% of the transport sector’s CO2 emissions. But as with transoceanic aviation, hyperloop is unlikely to be a substitute for ship transport.
Rail: Like ships, transport by rail is very energy efficient. Worldwide, rail accounts for about 8% of transportation-miles for people (around 2.5 trillion passenger miles) and 7% of freight-miles, yet it consumes only about 2-3% of the transportation sector’s energy. Rail is a complicated category. It includes urban metro and light rail, as well as longer-distance conventional and high-speed rail. Also, there are great regional differences. In the U.S., long distance rail is mostly used for freight. In India, long-distance passenger rail is pervasive and a part of the transportation culture. In China, long-distance travel is also commonly by rail, and this is increasing further as high-speed rail is expanded. It seems likely that hyperloop would be a viable substitute for most rail-freight, and for a significant fraction of long-distance passenger rail. It is easy to imagine that more than half of global emissions from rail could be eliminated with carbon-free hyperloop. This is a real benefit, though less than the reductions from road and aviation modes.
What can we conclude from this thought experiment?
Hyperloop would change how we travel and transport goods.
• It could reshape freight movement by absorbing a large fraction of over-the-road trucking.
• It could substitute for much domestic commercial aviation (but not transoceanic flights).
• And it could replace much of the freight and passenger traffic of conventional and high-speed rail.
It would have little impact on overall automobile miles traveled because of the dominance of short local passenger trips. But it could substitute for long-distance highway trips. And it would not affect ship transport, although it could greatly change port operations. With its impact on trucking and passenger road-trips, perhaps there would be less soul-destroying traffic on highways between cities.
Hyperloop could also have a very large environmental impact by reducing the CO2 footprint of transportation. The footprint of global transportation could perhaps be reduced by 25% or more by replacing most long-distance truck transport and a large fraction of airline flights, along with some savings from reduced car and rail emissions. That’s a huge benefit from implementing a single technology.
The solution of our dependence on fossil fuels and their harmful greenhouse gas emissions will be solved by many changes in how we power our world. This thought experiment indicates that hyperloop can lead the way, and be a big part of that solution!