The future of air travel hinges on whether sustainable aviation fuels can scale fast enough to matter. I've read that SAF currently accounts for less than 0.1% of global jet fuel, and production costs are roughly three to four times higher than conventional kerosene. Even with mandates in Europe and the US, airlines like Delta and United are only targeting 10% SAF by 2030, which feels painfully slow against rising passenger numbers. Is that genuine progress or just a well-marketed stall while we keep burning fossil fuels at 30,000 feet?