14 July 2022, Renew Economy: The madness of cutting down forests to grow food crops for supersonic aircraft biofuels. Regular readers will recognise several recurring themes in my writing, including the risks involved with reviving carbon-intensive supersonic aircraft and the challenges of scaling sustainable aviation fuels (SAFs). In this installment I deal with both. In June 2021, United Airlines announced that it intends to purchase 15 “Overture” aircraft from Boom Supersonic, with an option to purchase 35 more. In June 2022, United CEO Scott Kirby reaffirmed that United’s purchase remains “on track”. Those planes, we were originally told, will operate on 100% synthetic SAF produced from renewable electricity. In a January 2022 study conducted in partnership with MIT we concluded that even such a high-integrity “e-fuel” isn’t likely to mitigate the climate impact of supersonic aircraft. Unfortunately, the prognosis for delivering supersonic aircraft that burn clean fuels has gotten even bleaker. Last September, the Biden administration announced the “Sustainable Aviation Fuel Grand Challenge”, a whole-of-government initiative to spur the production of 3 billion gallons of SAF by 2030. That’s more than a 100x increase from 2020 global production. Read more here