The agriculture sector emits nearly 25% of total greenhouse gases globally, according to UN Environment Programme. Rapid deforestation to accommodate farmlands is one of the leading causes of global warming. According to World Wildlife Fund, the earth is losing forests at a rate equivalent to 27 soccer fields per minute to unsustainable and illegal farming practices amid a swift surge in food demand.
Farming, of course, is not the only sector responsible for exacerbating global warming. But just as it has significant GHG emissions, it also has a huge potential in contributing to energy transition, particularly in the growth of sustainable aviation fuel.
When it comes to climate change and decarbonization, SAF has become one of the most talked about topic in recent years. At a time when the threat of global warming is escalating, governments have begun to focus on reducing GHG emissions through any means necessary. But it is easier said than done.
Aviation's carbon footprint
The aviation sector emits nearly 1 billion mt of CO2 annually, accounting for 12% of global transportation emissions, the US Department of Energy said.
With air travel demand expected to increase by an average of 4.3% per annum over the next 20 years, according to a UN report, the volume of CO2 that may be emitted by airlines into the atmosphere in the coming years will further stress the environment.
This naturally brings the spotlight firmly on the urgent decarbonization of the aviation sector, which has committed to achieve net-zero emissions by 2050, and SAF is key in attaining this ambitious goal.
SAF is a biofuel that has similar properties to conventional jet fuel but with an 80% lower carbon footprint. Some of the feedstocks to produce SAF are corn, oilseeds, sugarcane, agricultural residues, used cooking oil, biological waste and animal fat.
According to the DOE, SAF will not only reduce GHG emissions, but it will also provide economic opportunities for farmers and even boost aircraft performance.
By growing biomass crops for SAF production, farmers can earn more money during off seasons by providing feedstocks to this new market, while also securing benefits for their farms like reducing nutrient losses and improving soil quality, the DOE said.
Biomass crops can control erosion and improve water quality and quantity, increase biodiversity and store carbon in the soil, which can deliver on-farm and environmental benefits across the country, the DOE said.
Producing SAF from wet wastes, like manure and sewage sludge, also reduces pollution pressure on watersheds, while keeping potent methane gas – a key contributor to global warming – out of the atmosphere, according to the DOE.
Despite its numerous advantages and perks, SAF is not devoid of challenges.
First of all, the adoption of SAF is still at its nascent stage despite initiatives by nearly 30 countries worldwide to invest in renewable fuel projects.
Global SAF production was estimated at 240,000 mt in 2022, up 200% on the year, according to an International Air Transport Association report, but it was only 0.1% of the total jet fuel output of 254 million mt.
So, the IATA's goal of sourcing sufficient SAF to meet 100% of aviation fuel demand by 2050 looks little quixotic.
Cost is also an issue. It is estimated that SAF currently costs nearly 2-2.5 times more than conventional jet fuel, making it economically unfeasible for the aviation industry to invest in biofuel production and use.
Platts, part of S&P Global Commodity Insights, assessed Jet Index Global at $1,042.56/mt and Sustainable Aviation Fuel Cost of Production (UCO) North Asia at $1,825.48/mt Sept. 19.
Infrastructure for production, storage and distribution of SAF is also currently limited, making it very tough to scale up output and be competitively priced.
If that's not all, there are other challenges which are no less daunting. Limited feedstock availability, lack of globally recognized production standards and complex certification processes are making SAF adoption very difficult. There is also a fear that diverting crops towards biofuel production can push food prices, which are already on an upsurge amid several supply shocks in recent years.
There is also a rising concern among environmentalists that clearing forests to grow crops for fuel is contrary to solving global warming. This argument does make you pause a bit and contemplate.
While SAF seems to be the golden ticket for agriculture to reduce its burgeoning net greenhouse gas emissions and gain some redemption, there are challenges galore, and the path looks hazy.
But as Charles Darwin aptly put it: "The most important factor in survival is neither intelligence nor strength but adaptability."
Everything now depends on the collective resolve of governments and people to reduce their carbon footprint in whichever way possible. And SAF could be the first milestone on our path to salvage the blue planet.