Although there is obviously still effort being put into the supersonic programs, aerospace giants like Boeing and Airbus are working pretty hard to get a reduct

Although there is obviously still effort being put into the supersonic programs, aerospace giants like Boeing and Airbus are working pretty hard to get a reduction in NOx, emissions and fuel consumption. We have gone a long way in designing a good aircraft, and have been making it more efficient over the last few years. One of the primary goals of these manufacturers right now is to become more efficient. [1] NASA has some mid-term goals for 2035 in terms of emissions, NOx and fuel consumption, in terms of TRLs. [1] https://aero.larc.nasa.gov/files/2012/11/Low-Noise-Subsonic-Challenge-2016.pdf https://aero.larc.nasa.gov/files/2012/11/Low-Noise-Subsonic-...