Can biofuels really fly?
The aviation industry is under increasing pressure to reduce its greenhouse gas emissions. As the world deals with climate change, finding cleaner ways to power flights has become a top priority. One solution gaining attention is Sustainable Aviation Fuel, or SAF. These alternative fuels offer a promising path toward lower emissions in air travel, but making them a widespread reality will not be easy.
Aviation accounts for about 2 to 3 percent of global carbon dioxide emissions. That share could grow significantly in the coming decades if the sector continues to rely on fossil fuels. Unlike cars or buildings, where switching to electricity is becoming more common, long-distance flights remain difficult to decarbonize. Electric and hydrogen aircraft are being developed, but they are not yet ready for large-scale commercial use. That’s where SAF comes in. When produced sustainably, SAF can reduce carbon emissions by up to 80 percent over its full lifecycle compared to conventional jet fuel. This makes it a key part of the industry’s plan to reach net-zero carbon emissions by 2050.
Sustainable Aviation Fuels are made from renewable resources or waste materials, rather than petroleum. These sources include used cooking oil, agricultural leftovers, forestry residues, algae, and synthetic fuels made using renewable electricity and captured carbon dioxide. Unlike traditional jet fuel, SAF is created from carbon that is already part of the natural carbon cycle, which means it can be burned with much less long-term impact on the atmosphere.
One major advantage of SAF is that many versions are known as “drop-in” fuels. This means they can be blended with regular jet fuel and used in existing aircraft engines and fueling systems without the need for new infrastructure. Current regulations allow SAF to be blended up to 50 percent with traditional jet fuel, though researchers are working on increasing that limit. New production methods are also emerging, such as fuels made using renewable power and direct air capture, which could lead to even cleaner options in the future.
Despite its potential, SAF faces serious challenges. One of the biggest problems is supply. Right now, less than 0.1 percent of global jet fuel comes from sustainable sources. Producing enough SAF to meet future demand will require enormous investment in new facilities, technologies, and supply chains.
Cost is another major issue. SAF is currently two to five times more expensive than regular jet fuel. That makes it difficult for airlines to use SAF without financial support, especially in a highly competitive industry where fuel is one of the largest expenses. Until costs come down, government incentives and regulations will be essential to encourage adoption.
There are also environmental concerns about how SAF is produced. If feedstocks are not carefully chosen and managed, they can cause new problems. For example, growing crops for fuel can lead to deforestation, harm biodiversity, and drive up food prices. Some production processes use large amounts of water and energy, raising questions about overall sustainability. Experts emphasize the importance of full lifecycle analysis to make sure SAF actually delivers the emissions reductions it promises.
Government policy and infrastructure are key to making SAF work. Policymakers can help through tax credits, subsidies, and blending mandates that create a stable market for SAF. Airports also need to update fuel storage and distribution systems to handle greater volumes of sustainable fuel.
Despite the obstacles, some progress is being made. Airlines like United, Delta, and Lufthansa are investing in SAF projects and conducting test flights. In 2023, Virgin Atlantic completed a transatlantic flight powered entirely by SAF—a major milestone in demonstrating its potential. Partnerships between fuel producers, airlines, and research institutions are growing, and governments in the U.S. and Europe are beginning to back SAF development with funding and policy support.
Experts say that if enough investment and support are sustained over the coming years, SAF could make up a significant share of aviation fuel by 2040. But this will require ongoing technological advances, better policies, and careful planning to ensure sustainable feedstock supplies. While SAFs won’t solve all of aviation’s climate problems, they are one of the most realistic tools available today. If developed responsibly, they could help the world keep flying, without warming the planet as much in the process.
