Life Cycle Assessment (LCA) results provide insights into the environmental sustainability of the different methods. The ETJ production in China using direct fermentation and gasification indicated the least GHG emission at 31.66 gCO2eq/MJ jet fuel ; PtL production in the UK revealed a greenhouse gas potential of 21.43 gCO2eq/MJSAF, which is below the UK mandate of a 50% emission reduction compared to fossil jet fuel ; A unique method in the US integrating Fischer-Tropsch fuel production with corn ethanol by-product CO2 showcased an impressive WTW GHG emissions reduction by 90-108% against petroleum fuels ;