Scientists want the Paris Olympics to dump Toyota’s Mirai as an official car. Here’s why

A group of 120 scientists, engineers and academics have penned an open letter calling on the Paris Olympics’ organizers to ditch Toyota’s Mirai as the official vehicle of the Games, saying the hydrogen-powered car undermines the event’s green credentials.

Cars that run on hydrogen emit zero carbon at the tailpipe, but 96% of the world’s hydrogen is still derived from fossil fuels like methane gas. That makes most hydrogen-powered cars much more polluting than battery electric vehicles, or EVs, and only marginally cleaner than traditional combustion engine cars.

Toyota is supplying the Game’s official fleet, which includes 500 Mirai cars and 10 coaches that run on hydrogen, as well as 1,150 EVs, to ferry athletes around. It says it will run the Mirais on hydrogen derived from water and organic matter, generated with renewable sources.

But the letter’s authors still oppose the car’s promotion, because in reality, consumers who buy the Mirai will almost certainly run it on hydrogen derived from planet-heating fossil fuels.

“We are writing to express our concern that Toyota’s promotion of a hydrogen car is scientifically misaligned with net-zero and will damage the reputation of the 2024 Games,” wrote the authors, who include scientists and engineers from the University of Cambridge, Oxford University and the University of Colorado.

“Opportunity remains to reroute, and we urge that you require Toyota to replace the Mirai with a Battery Electric Vehicle as the official Games vehicle.”

The Paris Olympics organizers are aiming to host the “greenest-ever Games,” hoping to halve the carbon footprint of the major sporting event, compared with levels in the 2010s. To do that, it will attempt to run the Games entirely on renewable energy.

CNN has reached out to the organizers for comment.

The letter is the latest criticism of Toyota, which has faced pushback for its “multi-path strategy” to decarbonizing its vehicles, which critics say focuses too little on EVs. Passenger cars and vans account for around 10% of the world’s energy-related carbon pollution.

Toyota, the world’s biggest automaker, is investing in EVs, but has focused heavily on hybrids and plug-in hybrids. It is also one a few major automakers betting on hydrogen-powered vehicles, as well.

CNN has previously reported that the company has aggressively lobbied governments around the world, including in the United States, to delay the phase-out of combustion engine cars and to have other types of cars, such as plug-hybrids, included in decarbonization plans.

“The mix of different vehicle technologies in the (Olympics’) fleet reflects Toyota’s global multi-path strategy that the right solution is needed for differing situations to decarbonize transportation dependent on diverse energy availability, infrastructure and customers’ needs,” Toyota Motor Europe told CNN in a statement.

The statement adds that Toyota believes hydrogen-powered cars will have a role in the world’s net-zero future, saying hydrogen vehicles can generally go for longer without refueling. Refueling a hydrogen-powered car is also currently much quicker than recharging an EV, though rapid-charge technology for EVs is improving.

Toyota is working on up to 10 different uses for hydrogen in its vehicles.

“These include passenger cars and heavy commercial vehicles, trucks and buses, as fuel-cell technology enables extended range and rapid refuelling,” the statement said.

Hydrogen vehicles have so far failed to take off as a popular choice for consumers, and very little infrastructure to refuel with hydrogen exists.

Green hydrogen — which is made from the electrolysis of water using renewable power, like wind and solar — is not yet available to drivers and is unlikely to be offered at the pump any time soon, experts say.

For more CNN news and newsletters create an account at CNN.com