Economics of aviation fuel decarbonization: A preliminary assessment

Limiting global warming to 1.5 degrees C requires decarbonizing all sectors of the world economy by mid-century, only 30 years from now. For sectors such as aviation, decarbonization will be challenging: There are currently no working examples of long-distance, zero-carbon commercial aircraft. While aviation emissions comprise less than 3% of world greenhouse gas emissions, aviation emissions are rising quickly. Previous studies describe technical feasibility of decarbonization options; this study compares the economics of decarbonization paths to make a preliminary assessment of cost effectiveness. We present economic data on three potential aviation decarbonization paths: 1) continuing use of fossil kerosene with direct air capture and sequestration of carbon dioxide emissions elsewhere; 2) producing hydrogen fuel from renewable electricity to replace fossil kerosene; and 3) replacing fossil kerosene with synthetic renewable kerosene produced from renewable energy. We combine estimates from the literature and expert opinion to assess the likely costs of each potential decarbonization path. Fossil kerosene plus remote sequestration appears to have the lowest short-term private cost, but is not completely sustainable; renewable kerosene could be available soon but likely has the highest cost; and hydrogen may be the least expensive fuel, but requires development of hydrogen-powered aircraft and infrastructure. Air fare changes resulting from any of the three paths are likely within the range of those seen in the last few decades. This study demonstrates that aviation decarbonization is economically feasible, through at least three paths.