Everyone loves a vacation. And a good vacation generally includes air travel. While the transportation industry has recently been heavily criticized for its global contribution to greenhouse gas emissions, one of the largest sectors of the transportation industry, aviation, has not been the focus of attention. People are rightfully concerned about the emissions from passenger vehicles, but overlook that aviation also is one of the largest contributors to global warming, despite the fact that aviation traditionally carries hundreds of people at a time. Thankfully, sustainable aviation fuel (SAF) has emerged as a promising solution to reducing carbon emissions from planes and other aviation forms. SAF is a biofuel that is used to power aircrafts, but with a significantly less carbon footprint than traditional jet fuel.
As always, we will jump into the numbers. Overall, aviation accounts for around 4% of global CO2 emissions, more than the total of most countries. In fact, aviation’s annual 100 billion tonnes of carbon emissions are higher than that of Germany. If aviation were to be a country, it would be the sixth largest contributor to greenhouse gasses. Additionally, airplanes emit approximately 100 times more CO2 than a shared bus or train ride. The overall carbon emissions from SAF can be up to 80% lower than emissions from conventional fuel. Even if blended 50% with conventional fuel, the reduction in carbon emissions is still up to 40%. It is estimated that a transition to 90% carbon-neutral fuel mix by 2050 would prevent aviation’s contribution to global warming.
The biggest plus of SAF is that it is made from plentiful materials. SAF can be made from oil seed plants and agricultural and forestry residue, organic municipal solid waste, fats, oils, and greases from cooking waste and meat production, algae, and industrial carbon monoxide waste gas, all of which have a lower life-cycle carbon intensity than traditional petroleum-based fuels. Using plant feedstocks to produce SAF is incredibly sustainable because it creates a loop of energy usage without emitting any. Plants are able to absorb carbon from the atmosphere as part of photosynthesis. Then the plants are turned into the fuel, releasing the carbon back into the atmosphere when it is burned. This way, the carbon is “defossilized” through the SAF process by using carbon that is already existent in the biosphere rather than the fossil-carbon used in traditional fuel. On the other hand, waste as feedstock for SAF recycles the carbon present in it, reducing the methane emissions which come from decomposing waste in landfills.
Another benefit is that SAF is considered a “drop-in” fuel meaning that it is certified to be blended with conventional fuel. This means that airplanes do not need to replace engines or fueling infrastructure, dropping the potential costs associated with the switch to more sustainable energy sources. Currently, there exist 7 different SAF production processes that are certified to be used in planes.
Other than simply greenhouse gas emissions, SAF also prevents emissions of other pollutants that come from conventional fuel. SAF emits fewer sulfur oxides and particulates, less carbon monoxide, and fewer hydrocarbons. Because SAF reduces the number of particles in the exhaust, contrail formation is diminished, a major contributor to global warming. This also dramatically improves the local air quality.
However, there are also some challenges that come with the transition to SAF. You could probably already guess that price would be at the top of the list as it is with all green transitions. SAF costs typically 4-5 times more than conventional jet fuel. However, I believe this number would dramatically drop if SAF was more widely adopted and with increased infrastructure to support it. As of 2019, SAF accounted for less than 0.1% of the 96 billion gallons of total aviation fuel consumption. SAF production will also require using a greater variety of feedstock, again something that could be accounted for with more investment and infrastructure. Although there are millions of tonnes of biomass potentially available as fuel, more than enough to cover U.S. aviation fuel demand, production into SAF is required. Lastly, in order to adopt SAF, favorable tax policy is required to encourage its production. Thankfully, the Biden-Harris administration is already working on the solution by introducing initiatives which will support the growth of sustainable fuels.
I believe that SAF can become the future of clean, long-distance transportation. The numbers back me up because the worldwide sustainable fuel market is projected to have a 56% compound annual growth rate over 10 years. Although there are some drawbacks as of now, they all can be prevented with a global shift to SAF. As long as corporations are apprehensive to shift, we will not be able to invest the proper time and money to increase the infrastructure necessary to increase its reach. Hopefully next time you take a plane trip, it will be powered with biofuels!
Works Cited
EESI), Environmental and Energy Study Institute. “An Introduction to Sustainable Aviation Fuels | Article | EESI.” Www.eesi.org, 1 Feb. 2022, http://www.eesi.org/articles/view/an-introduction-to-sustainable-aviation-fuels.
Kimbrough, Liz. “How Much Does Air Travel Warm the Planet? New Study Gives a Figure.” Mongabay Environmental News, 6 Apr. 2022, news.mongabay.com/2022/04/how-much-does-air-travel-warm-the-planet-new-study-gives-a-figure/.
“What Is and What Are the Benefits of Sustainable Aviation Fuel? – INFLOR®.” Inflor.com, 13 Dec. 2022, inflor.com/blog/benefits-of-sustainable-aviation-fuel/.
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