With climate change reports getting more urgent every year, Tesla’s recent announcement that it will begin offering a $35,000 Model 3 sedan couldn’t come too soon—but automobiles are only part of the problem, and may not even be the worst contributor to climate change going forward. Unless electric airplanes are also developed to replace our current fuel-burning aircraft, replacing the entire world’s automobiles with electric cars might not be enough to prevent the worst effects of climate change.
Energy Efficient Cars
On paper, automobiles produce more than half of the carbon emissions by metric tonnage of the entire transportation sector, while air travel produces only about 9% of the transportation sector's emissions, so it seems counter-intuitive that developing an electric airplane might be even more important than developing an electric automobile.
Dig deeper into the numbers, as well as the science and the current trends in the industry, and it soon becomes apparent just how unsustainable fuel-burning aircraft are going forward and how, without corrective action, the planet may soon be choking on airplane emissions no matter how many Model 3's are on the road.
When you look at just the amount of emissions produced, a round trip flight from New York to Los Angeles produces 20% as much greenhouse gas (GHG) emissions as a car does in an entire year.
Unfortunately, almost three times as many people fly every year as own a car, 3.1 billion airline passengers to 1.4 billion cars on the road. And the number of airline passengers are expected to soar over the next 20 years as China’s emerging middle class and the growing economic power of India will bring unprecedented demand for air travel.
As bad as those numbers may seem, air travel is already a bigger contributor to climate change than automobiles.
The difference in emissions figures by metric ton obscures the different impact these emissions have. Cars operating at ground level emit more GHG than an average aircraft flight, but airplanes fly in the stratosphere, where their GHG emissions have a disproportionate impact on climate change, possibly as much as 2.7 times ground-level emissions.
Our current level of air travel is simple environmentally unsustainable and we are about to add billions of more airline passengers to the mix. This makes fuel-burning airplanes one of the biggest unaddressed challenges of the climate crisis.
Why Conservation and Fuel Efficiency Won’t Help
One of the biggest challenges is educating the public on the impact of air travel on the climate. Everyone knows how much cars pollute the air, we’ve been hearing about it for decades now. Laws have been passed and fuel efficiencies introduced on vehicles that people drive every day and refuel once or twice a week.
The costs are immediate and we are regularly reminded of the swings in fuel prices and see the belching tailpipes of cars in traffic. Airplanes, meanwhile, are rare expenses that belch out far more emissions than the car in front of us, but they are literally doing so tens of thousands of feet above our heads.
The best way to impress upon the public the true emissions cost of air travel through a carbon tax is nearly a political non-starter for democratic leaders.
Tony Blair asked a Parlimentary commission looking into an airline flight tax in 2005 an important question, “[h]ands up round this table how many politicians facing a potential election in the not too distant future, who would vote to end cheap air travel?”
Seeing no initial response, Blair added, “Right—none.”
As for reducing fuel consumption through efficiency, the carefree days of cheap airplane fuel have long since passed.
Airplane makers have been scrambling for over a decade to redesign aircraft to perfect its aerodynamics to reduce drag and doing everything they can to make them lighter to appeal to the oil price sensitive airlines, whose largest expense by far is the cost of fueling their airplanes.
Just about all the efficiency we can squeeze out of a large, aluminum flying machine traveling hundreds of miles an hour at 40,000 feet have already been introduced. There isn’t much more we can gain there.
Why Electric Airplanes Are Impossible To Scale Right Now
So where is the Tesla Motors of aircraft manufacturing?
The idea of an electric airplane or aircraft isn’t new. Nikola Tesla had a plan to build wireless electricity transmitters at regular intervals along major routes to power electrified air travel, though he never managed to build the transmitter itself, much less the network he'd need to attempt such a system.
So why has no one else tried it since? Airplanes require incredible amounts of energy to lift off the ground, so the more weight you add to the craft, the more power you will need to lift it. The key roadblock to the electric airplane then is a matter of simple math.
Current lithium-ion batteries can contain 1,000,000 joules of energy per kilogram. Airplane fuel contains 43,000,000 joules/kg.
Add an electric battery to an airplane that is 43 times the weight of jet fuel and you’ll be lucky if you can get the plane to taxi out of the hanger it was built in; forget about getting it into the air.
When Might We See A Commercial Electric Airplane?
In the conventional sense of your typical airliner, it will be decades before batteries are sufficiently energy-dense enough to power an airplane, but countries like Norway are encouraging this long term development by requiring that all their airplanes be electric rather than fuel-burning by 2040.
“It is certainly a long way, but because the time scales of aviation are so long, [airliners] tend to live for 20 to 30 years, we need to start looking at these technologies now so they’re available in 2050,” says to Andreas Schäfer, professor of energy and transport at University College London.
Is there anything we can do before then, though? In thirty years time, it might be too late for the planet, so more immediate solutions are clearly needed and the best place to find them is to reconsider air travel fewer than 600 nautical miles, which comprise about half of all flights flown every year.
These short distance shuttle flights are incredibly inefficient since take-off, landing, and taxiing produces about 25% of the flight's total emissions, so on short flights, this inefficiency is amplified. The more planes you have taking off and landing, the worse this problem gets overall.
These flights are a prime candidate for electrification since electric airplanes with a range of about 600 nautical miles will be available much sooner than those capable of longer ranges. They may be smaller than standard aircraft, but the reason why airlines try to pack as many passengers into an aircraft is more about trying to optimize fuel costs than it is anything else. The more passengers you can move with the same amount of fuel, the better.
Eliminate that fuel cost and replace them with a much larger fleet of smaller, air taxi style electric airplanes and airlines could save significantly in the process. Bell Helicopters and Boeing are already developing urban air taxi vehicles, so longer range electric aircraft might not be too far off.
Airbus is even reportedly looking into electrifying its short to medium range aircraft with capacities of 60 passengers or less, exactly the kinds of planes used in the short-range commuter and business flights whose emissions are such a problem.
Ultimately, taking half the world’s fuel-burning aircraft out of the emissions equation entirely might just give us the time we need to develop batteries capable of powering a Boeing 747-sized craft from New York to Los Angeles. It's definitely a challenge, but one we need to tackle.
Whether we ever see an electric airplane that big or not, we have to do all we can to develop it if possible, otherwise the alternative is a climate catastrophe whose costs both human and material will make the oil shocks of recent years pale in comparison.