SAF and CORSIA
CORSIA, or Carbon Offsetting and Reduction Scheme for International Aviation, is expected to provide around $40 billion in funding for climate projects worldwide.
The mandatory stage for CORSIA will begin in 2027 and will cover nearly all international flights between participating states. Meanwhile, the first rounds are already on their way, divided into segments of a voluntary pilot phase from 2021-2023 and another voluntary phase from 2024-2026.
This means that all qualifying flights between two states participating in the voluntary rounds will be subject to the offsetting requirements, regardless of whether the operator is itself based in one of these states.
Airlines and other air operators obliged to participate in the scheme can also choose to offset CO2 emissions through the purchase and use of sustainable aviation fuel (SAF) or lower carbon aviation fuel.
Meanwhile, not any sustainable fuel will do. In order to be eligible for CORSIA, the SAF needs to be certified through approved mechanisms according to a set of criteria determined by ICAO.
In July 2022, the very first CORSIA-certified sustainable aviation fuel was delivered to a commercial airline as part of a pilot project between Neste and American Airlines.
The fuel was certified through the International Sustainability and Carbon Certification (ISCC) system. This is currently one out of two accredited pathways for SAF certification for CORSIA. The other is via the RSB - the Roundtable for Sustainable Biomaterials.
What Are CORSIA-Eligible Fuels?
According to Annex 16 in Volume IV of ICAO Resolution A41-22, CORSIA defines sustainable fuels as follows,
“A CORSIA sustainable aviation fuel or a CORSIA lower carbon aviation fuel, which an operator may use to reduce their offsetting requirements.”
A CORSIA sustainable aviation fuel is further defined as a renewable or waste-derived aviation fuel that meets the CORSIA Sustainability Criteria. Meanwhile, a lower-carbon aviation fuel is a fossil-based fuel that meets the same criteria.
As previously mentioned, compliance with the CORSIA criteria requires an independent attestation by an ICAO-approved Sustainability Certification Scheme (SCS). The air operator wishing to use sustainable or low-carbon aviation fuel toward offsetting emissions must then provide evidence of this certification in the reporting.
The actual emissions reduction offset for which the air operator will be eligible is then calculated using a formula comparing the lifecycle emissions of the fuel in question to those of regular Jet A.
Under CORSIA, there are two ways to calculate lifecycle emissions of fuel. The first is to apply the default emission values for SAF as provided by ICAO, given the feedstock and conversion process. The second allows for a calculation of emissions over the lifecycle for a specific SAF through a methodology also provided by ICAO.
The SCS certifying the fuel is responsible for calculating the right value for lifecycle emissions, as well as making certain that the sustainability criteria are met.
Criteria
Even with the best intentions, replacing fossil-based fuels with bio-based sources, necessary as it is, could contribute to issues like deforestation, loss of biodiversity, global hunger, and water pollution. All in all, it could end up causing more harm than good to communities and the planet.
For a fuel to be eligible for CORSIA certification, it must therefore meet specific criteria set out by ICAO. The first two are currently in effect. Meanwhile, another ten will come into play for fuels produced after January 1, 2024.
Greenhouse Gas Emissions
“Principle: CORSIA eligible fuel should generate lower carbon emissions on a lifecycle basis.”
Whether certified through the ISCC or the RSB, CORSIA-eligible fuel must generate a minimum of 10% less greenhouse gas emissions over the course of the lifecycle compared to conventional fossil-based Jet A.
Considering that most advanced biofuels today offer a reduction of about 70-80% of carbon emissions compared to fossil fuels, this is not a very high ask.
Indeed, the implementation of CORSIA has also been criticized for opening up for the inclusion of already mentioned so-called lower-carbon fossil-based fuels, such as natural gas and propane, rather than only sustainable fuels from renewable sources.
Carbon Stock
“Principle: CORSIA eligible fuel should not be made from biomass obtained from land with high carbon stock.”
Carbon stock is the amount of carbon held in a carbon pool at a given time. Carbon pools are reservoirs or systems of specific habitats that have the potential to store (or release) carbon.
This principle states that for fuel to become CORSIA-certified, the feedstock can not come from biomass obtained from land converted after 1 January 2008 that was primary forest, wetlands, or peat lands, nor can it contribute to the degradation thereof.
Further feedstock criteria
The other criteria that will need to be met starting in 2024 are specified under the subcategories water, soil, air, conservation, waste and chemicals, human labor rights, water use rights, local and social development, and food security.
Challenges With Documentation For SAF Feedstocks
Setting blending mandates and developing criteria for SAF may be the easiest part of the equation as aviation attempts to pivot away from fossil-based fuels.
It is not only that vast quantities are needed at a reasonable price independent of geographical location (something Book & Claim mechanisms are attempting to facilitate), but operators must also make certain the SAF reduces the amount of CO2 it claims to.
The traceability of SAF feedstock and correct CO2 lifecycle calculations are highly complicated procedures. As the industry continues to grow to a predicted $15 billion by the end of the decade and new feedstocks are certified, the regulatory landscape will continue to evolve, as will accountability and accounting mechanisms.
Not all feedstocks are created equal, and just because they may be of bio-based origins, that doesn’t mean that they will automatically have a low-carbon impact. Knowing the specifics of where the feedstock is derived from is critical to understanding what overall impact it has on the environment.
Tracing SAF back to the source can often be challenging and time-consuming, but it will become absolutely necessary, especially when using sustainable fuels toward your CORSIA environmental impact plan.