Reviving Supersonic Jets Will Damage the Climate

https://www.nytimes.com/2018/06/11/opinion/reviving-supersonic-jets-will-damage-the-climate.html

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Traveling by plane is one of the worst things you can do for the environment. On average, one nonstop round-trip flight from the United States to Europe releases about one metric ton of carbon dioxide per person, or about what a resident of Honduras emits in a year.

Unfortunately, several American start-ups are proposing to make the problem even worse by reviving the bad old idea that the world’s jet-setters need to break the sound barrier to get where they’re going.

The aviation industry, recognizing its impact on the climate, belatedly adopted a global climate plan for commercial aviation in 2016 that is scheduled to take effect in 2021. But returning commercial supersonic transport aircraft, or SSTs, to the skies could upend those efforts.

Supersonics were all the rage when testing began for commercial flights in the 1960s, but the planes ran into problems because of high costs and pollution concerns. Ultimately, only the Concorde, a British-French collaboration, ever saw long-term commercial service after its inaugural flight in 1976. The development of that aircraft was famously expensive, costing about 10 times its initial budget.

The Concorde was also a big polluter, burning two tons of fuel just taxiing and four times as much fuel per passenger as a Boeing 747 jumbo jet. Because of its sonic boom, the jet was not allowed to reach supersonic speeds over land. The crash of Air France Flight 4590 in 2000 was the coup de grâce, but well before then it was apparent that without supercheap fuel, the economics of extended supersonic flight just didn’t work. In 2003, the Concorde was retired.

Today, American start-ups like Boom, Aerion and Spike are aiming to revive supersonic air transport. President Trump has tweeted that new supersonic aircraft demonstrate the “Great American Spirit.” Under his watch, the Federal Aviation Administration has moved to expedite flight testing and certifying of new SSTs. While slashing the F.A.A.’s research budget, the Trump administration found almost $250 million to subsidize a new “low boom” demonstration supersonic aircraft.

Among the enthusiastic supporters of the supersonic revival is Richard Branson, founder of the Virgin Group, which includes the Virgin Atlantic airline. His company has partnered with Denver-based Boom, which aims to bring a 55-seat SST into service by 2023. Virgin has offered technical, engineering and flight test support for the design.

In contrast to President Trump, Mr. Branson has sought to establish himself as an environmentalist. He once declared that saving the world was good business. He has been sharply critical of Mr. Trump’s decision to withdraw the United States from the Paris climate accord. But with his foray into SSTs, he risks sullying his reputation.

Climate scientists say that we can emit only so much carbon dioxide and still remain within the temperature limit set by the Paris accord. New supersonic aircraft will help devour that carbon budget faster than ever. These aircraft will also pollute our skies and, with their sonic booms, break the calm we all need.

Boom claims that technology advances from subsonic aircraft since the 1970s — more fuel-efficient engines, lightweight and heat-resistant composite materials, and advanced aircraft design tools — plus the pluck of entrepreneurial private capital can succeed where the Concorde failed. A closer look reveals the cracks, though.

Even as Boom aims to develop a “new” supersonic plane, the underlying problems of supersonic flight won’t be easily overcome. A key barrier is noise itself. Despite its talk about “quiet” SSTs, Boom is supporting legislation that would exempt these jets from updated and more stringent noise standards for takeoffs and landings for new aircraft. That’s a pretty stunning lack of confidence in its ability to deliver “quiet.”

The legislation also contains a provision that could remove the 40-year-old overland flight ban for civilian supersonic jets. This means sonic booms would reverberate in communities below as these jets exceeded the speed of sound.

And because supersonic aircraft operate at very high altitudes, their emissions are expected to harm the atmosphere even more than subsonic flights.

According to a 1999 report by the Intergovernmental Panel on Climate Change, introducing 1,000 commercial SSTs more advanced than the Concorde could make the climate impact of airlines balloon by 40 percent by midcentury. That’s on top of the tripling of emissions already expected as more travelers take to the sky.

Today’s subsonic engines are better. Boeing’s state of the art Dreamliner is up to 80 percent more fuel-efficient than the 747. But whatever the technology, a supersonic plane unavoidably wastes a lot more fuel than its subsonic competitors. That translates to more air pollution, including lung-damaging nitrogen oxides and ultrafine particles. Wasted fuel, noisy skies and an unraveling climate — supersonic flight is an idea whose time has passed.

As we work toward real solutions for aviation’s part in the climate crisis, it is critical for leaders like Richard Branson to demonstrate true leadership. He can start by cutting ties with supersonic aircraft developers — before it really is too late.