Plausible pathways to net-zero emissions aviation
Author: ALEX MACHERAS
A new study in the peer-reviewed scientific journal Nature highlights plausible pathways to net-zero emissions aviation, including the relative potential and trade-offs of changes in behaviour, technology, energy sources and carbon equivalent removals. According to the IEA, in 2019, aviation accounted for 1.03GtCO2, or 3.1% of total global CO2 emissions from fossil fuel combustion. The report explains that recent analyses have evaluated the technological potential of powering aircraft with sustainable aviation fuels (SAFs), hydrogen or electricity and offsetting aviation emissions by removing equivalent quantities of CO2 from the atmosphere. SAFs include biofuels and synthetic fuels that are ‘drop-in’ replacements for jet fuel (that is, they would require little or no changes to existing aircraft and fuelling infrastructure) that meet ICAO’s sustainability criteria a net greenhouse gas emissions reduction on a life-cycle basis of at least 10% compared to fossil jet fuel, respecting biodiversity and contributing to local social and economic development. One of the conclusions from the study is that “further reductions will depend on replacing fossil jet fuel with large quantities of net-zero emissions”. Compared to conventional jet fuel, SAF can reduce up to 100% carbon emissions on a lifecycle basis, depending on the SAF technology used. Aircraft today are powered by liquid aviation fuel, made mostly from fossil fuel sources. Yet new fuels have been developed that have the potential to dramatically reduce aviation’s net CO2 emissions. Although supply is currently limited (0.01% of global jet fuel use), sustainable aviation fuels (SAF) are already in use today and take-up is increasing.