Flight or fantasy? Are alternative aviation fuels ready for take-off?
It is telling that COVID-19 is not the biggest challenge that the aviation industry currently faces. The long-term effects are uncertain, but some analysts believe that the aftershock of the pandemic will persistently reduce aviation demand growth. Nevertheless, COVID does not challenge the basic foundations of the passenger aviation industry. Climate change does.
Currently, it has been estimated that aviation contributes around 3.5% of anthropogenic net radiative forcing. As the number of flights increases while emissions from other sectors start to fall, this percentage is going to increase. That in turn will put more and more of a spotlight on aviation as a disproportionate contributor to the climate problem and could even challenge the aviation industry’s social license to operate.
This is not news to the airlines – it has been clear for many years that action would need to be taken to improve the carbon footprint of flying. Back in 2009, the aviation industry committed to a goal of reducing total sectoral CO2 emissions by 50% by 2050, compared to 2005 levels. Scenarios for delivering this commitment involve improved efficiency of new aircraft and operational savings, but the largest contribution comes from the assumption of a more or less 100% transition to the use of alternative aviation fuels. Up until recently it had been widely assumed that this would be dominated by the use of biofuels, but recently attention has also turned to the potential of electrofuels, which avoid some of the sustainability issues presented by such a largescale mobilisation of biomass resources.