Supersonic flight has superlinearly more drag than subsonic flight. IIRC, n^4 or n^5, while drag was normally n^2 kinda thing at subsonic speeds. Concorde was

Supersonic flight has superlinearly more drag than subsonic flight. IIRC, n^4 or n^5, while drag was normally n^2 kinda thing at subsonic speeds. Concorde was progress, but backwards progress in terms of what matters in terms of global warming (etc. etc.) You can reduce some drag by flying higher (thinner air, less drag effects), but that also requires more fuel to reach higher into the atmosphere. So its just inefficient all around.