Aviation, not shipping, drives EU CO₂ demand under current fuel mandates

Europe will need significant volumes of CO₂ to meet the criteria in predominantly ReFuelEU, and even more to reach net zero across the two sectors

I was asked to calculate how much CO₂ is needed for aviation and maritime transport in the EU. The calculators I previously shared on costs and volumes for these two sectors can be used to help show EU needs.

This article separates two questions that are blurred. First, how much CO₂ is implied by existing EU fuel mandates. Second, how much CO₂ would be required to reach actual net zero across aviation and maritime.

Aviation and maritime fuel demand is estimated at 45-50 Mtoe each in 2050 by the EU commission for the volumes covered by the ReFuelEU and FuelEU Martime directives. The EU assumes 35% biofuel and 35% e-fuel each for aviation. For maritime demand it assumes 58% biofuels (incl bio-LNG) and 21,6% for e-fuels, mainly hydrogen and ammonia (which does not require CO₂ as an input).

Under existing EU mandates, the primary source of structural CO₂ demand comes from aviation e-fuels. Additional CO₂ would be required only if the sectors were to move beyond mandate compliance toward full net zero.

Putting these numbers into the calculators give the following results in order to reach net zero across the sectors:

For aviation:

For marine transports:

Under a net zero framing, aviation requires roughly twice as much CO₂ as maritime (108.6 Mt vs 47.8 Mt). This is mainly due to the higher biofuel assumptions in maritime, and that e-ammonia, the assumed e-fuel for maritime, does not need CO₂ as an input.

For aviation the CO₂ needs are roughly the same for CO₂ as an e-fuel input (53Mt), as for mitigating unabated fuels to reach net zero (45,5Mt).

For maritime the greatest CO₂ volumes comes from unabated fuels. (However as previously stated, there is no policy to reach net zero for the total volumes covered by ReFuelEU and FuelEU Maritime. These directives volumes include CO₂ emissions outside of the union.)

The calculators also include CDR needed to offset emissions from the production of biofuels. Lifecycle emissions from biofuel production range between 0.6-2.4t CO₂ per tonne fuel. in the EU RED II, but could theoretically go down to zero. (There is no policy for offsetting these lifecycle emissions either though.)

For aviation RefuelEU gives a clear ramp up, enabling us to estimate the need for CO₂ over time. See the graph below.

This exercise shows that the EU will need significant volumes of CO₂ to meet the criteria in predominantly ReFuelEU. It is important to note that the EU does currently not explicitly address where that CO₂ should come from. The union would need even more CO₂ to reach net zero across the two sectors. The CO₂ could be sourced regionally, or carbon removal credits and e-fuel could be bought internationally.

I have separately argued that permanent CDR should be allowed to be used instead of e-fuels when CDR is the cheaper option, but this is not currently the case.

This article was made possible in part by support from Stiftelsen Futura.