Despite all these technological advances, a supersonic aircraft still cannot beat physics. Shock waves, and their associated drag, will still exist. So, a single supersonic aircraft will still produce considerably more carbon emissions than its subsonic counterpart.

The scaled-down prototype, nicknamed the "Baby Boom", broke the sound barrier for the first time during a test flight over the Mojave Desert in California in late January. The small jet, officially called XB-1, reached an altitude of 35,000 feet before accelerating to Mach 1.1 (844mph) – "10% faster than the speed of sound", said Sky News.

NASA is pushing the boundaries of supersonic travel with its experimental X-59 jet, a sleek, needle-shaped aircraft designed to fly faster than sound—without the disruptive sonic boom. The agency recently completed crucial engine performance tests,