A number of companies are flying SST Trial balloons, but we should all pop them now.
Things are different when you look up. Here on the ground, people try to make vehicles more energy efficient. Up in the sky, companies like Boom and Lockheed-Martin want to build supersonic planes that consume many times as much fuel per person as a subsonic plane. Boom is pitching their plane as a luxury service, but the real market for these little SSTs is the billionaire business jet, where money really is no object and CO2 problems are for little people.
We wondered previously if bringing SSTs back was a good idea, and apparently so does the International Council on Clean Transportation. They just released a study that concludes that the return of SSTs would double the amount of noise pollution around airports and cause disruptive sonic booms around the world, and then there is the carbon footprint:
The SST fleet would emit an estimated 96 (88 to 114) million metric tons (MMT) of CO2 per year, roughly the combined emissions of American, Delta, and Southwest Airlines in 2017, and an additional 1.6 to 2.4 gigatonnes of CO2 over their 25-year lifetime. That would consume about one-fifth of the entire carbon budget afforded international aviation under a 1.5°C climate trajectory, assuming that aviation maintains its current share of emissions.
The Boom people claim that their plane will put out the same CO2 per passenger as a subsonic business class passenger, and the ICCT disagreed with this previously. Now they back that up with new information and conclude that "new SSTs are unlikely to achieve fuel burn parity compared with current subsonic business class." Nobody really knows because these SSTs aren't off the drawing boards yet, let alone the runways. But they think that regulators should be developing "robust environmental standards to manage the expected noise and CO2 impacts of reintroducing commercial SSTs."
Regulators are faced with two choices: either to develop new SST standards that would allow those aircraft to produce more noise, air pollution, and climate pollution than new subsonic designs, or to apply existing subsonic standards to SSTs.
So while every generation of new planes is more fuel efficient, and some are even talking about electric planes, with SSTs we take a huge step backward. We don't even know what we are getting.
A comprehensive analysis of the climate impacts of these aircraft is recommended. Non-CO2 climate forcers, including water vapor, nitrogen oxides, black carbon, and aviation-induced cloudiness are expected to be significant given the high cruise altitude of SSTs.
Last year, Blake Scholl of Boom tried to justify his airplanes in a changing world, because "the need for improved human connection has never been greater."
While it is important to preserve mankind’s ability to flourish on our planet, it is also important to extend that ability. A key part of this flourishing, in our view, is supersonic travel. We look forward to working with innovators and scientists around the world to ensure that the future is both green and supersonic.
But the new report from the ICCT shows how silly and specious that statement is. These planes put out 3 to 9 times as much CO2 per person as regular economy flights, and we have to limit those. They are going to negatively affect everyone living under them or near the airports.
Really, given where we have to get to in carbon emissions, this is just a bad idea all 'round. But that won't stop a billionaire in a hurry, who wants his Lockheed X-59 QueSST business jet; they have probably already sent in their deposit checks.