Aviation pioneer Bertrand Piccard, known for Solar Impulse, is now leading the Climate Impulse project to revolutionize air travel using super-cooled liquid hydrogen split from water molecules. The goal is to fly a two-seater plane around the world over nine days fueled by green hydrogen, with first test flights planned for 2023 and the round-the-world trip set for 2028. The project faces challenges in untested innovations and the scalability of using liquid hydrogen for commercial flights. Despite the potential environmental benefits of green hydrogen, experts caution that its widespread adoption in aviation is still decades away due to current limitations in clean electricity production. The project aims to demonstrate the feasibility of green hydrogen-powered flight and its potential to significantly reduce carbon dioxide emissions in the aviation industry.