Rolls-Royce is testing the first jet engine powered by clean hydrogen. On 27 November 2022, the company fired up the engine on the ground using green hydrogen created from wind and tidal power. Together with partner easyJet, Rolls-Royce is hoping to fly commercial aircraft on clean hydrogen by the mid-2030s. Air travel generates over 2% of global CO2 emissions. Every year, passengers take 4 billion journeys. By 2050, it could be 10 billion. In 2021, the aviation industry came together to pledge to reach net zero by 2050. Sustainable aviation fuels (SAFs) will play a crucial role in the transition. Sustainable aviation fuels are typically biofuels made from vegetable oils or ethanol-based fuels derived from sugarcane. They already deliver up to an 85% reduction in emissions, but near-zero Sustainable aviation fuel could be ready by the mid-2020s. Watch the video to learn more about sustainable aviation fuels.