Aviation is running out of runway. Climate change is no longer a distant threat-it's warping tarmacs, grounding flights, and forcing a reckoning with the industry's soaring emissions. At the same time, demand for air travel is doubling, aircraft orders are locking in decades of carbon, and sustainable fuels still make up less than 1% of global supply. Sustainability in the Air: Volume 2 dives into this collision between growth and green ambition, offering a front-row seat to the startups, strategists, and skeptics working to close the gap.This isn't a book about blue-sky visions-it's a field report. From e-fuels to reimagined airframes, the most successful players aren't selling sacrifice, they're selling performance. If Volume One captured the spark of innovation, Volume Two charts the climb to commercial reality. It's a story of hard lessons, bold bets, and what it truly takes to build the future of flight.