In July, Lockheed Martin completed the build of NASA’s X-59 test aircraft, which is designed to turn sonic booms into mere thumps, in the hope of making overland supersonic flight a possibility. Ground tests and a first test flight are planned for later in the year. NASA aims to have enough data to hand over to US regulators in 2027.
The problem is that those emissions cause more warming at that altitude. So fly just above treetops, please. https://oncarbon.app/articles/non-co2-effects-aviation you need to at least triple it