Over the last threeyears, expansive energy transition and climate mitigationpolicy frameworks have been deployed on both sides of the Atlantic. They seek to reduce emissions from a wide range of economic sectors, includingelectricity generation,transportation, industry,and buildings. Within the transportation sector,batteryelectric vehicles (EVs) are widely regarded as the primary tool for addressing the majority of emissions. However,aviation and maritime applications are likely to require fuels for combustion engines for the foreseeable future. This report will examine the actions taken by the United States (US) and the European Union (EU), two regions commonly at the forefront of climate policy, to support the deployment of lower-greenhouse gas (GHG)fuel options in aviation and marine applications