Alternative fuels are the only means to reduce the climate change impacts of aviation until electrification of jetliners becomes feasible, which will be many decades. Interestingly, the largest radiative forcing from aviation is due to aviation-induced clouds, not carbon dioxide, and formation of these clouds is triggered by soot particles emitted from the engine. In a new paper, we show that alternative aviation fuels can have significantly lower sooting tendencies than conventional jet fuels. The alternative fuels in this work are made from food wastes, so they also benefit climate by reducing methane emissions from landfills. This work was done in collaboration with researchers at the National Renewable Energy Laboratory, the University of Dayton, and Oak Ridge National Laboratory. The full text is available at https://doi.org/10.1073/pnas.2023008118.