Your trash could fuel tomorrow's planes with 80% less carbon

Your old takeout containers, spoiled groceries, and discarded packaging aren't just waste — they're potential jet fuel. A new study calculates that the trash we throw away globally could produce 62.5 billion liters of sustainable aviation fuel per year, with a carbon footprint 80-90% smaller than conventional jet fuel.

Aviation is responsible for 2-3% of global greenhouse gas emissions, and it's stubbornly hard to decarbonize. Planes can't easily switch to batteries or hydrogen. That's why researchers are hunting for sustainable aviation fuels (SAFs) that don't require planting new crops or clearing forests — and waste looks increasingly promising.

"There is a wealth of organic waste deserving our attention," says Michael McElroy, a Harvard environmental studies professor involved in the research. "Using these wastes as feedstocks could reduce the cost of the decarbonization transition for hard-to-abate sectors." The appeal is practical: waste collection systems already exist in most cities, and the supply is constant year-round.

The challenge is that trash is messy. It's heterogeneous — a mix of different materials requiring multiple processing steps before it becomes fuel. Researchers had to work with real-world data from commercial facilities to understand whether this could actually work at global scale. Their conclusion: incorporating trash-based jet fuel into the aviation supply could cut the industry's greenhouse gas emissions by 16%.

The trickiest part is the first step — converting solid waste into a mix of gases through "gasification." "Its reliability and efficiency are crucial to the sustainability of green fuel synthesis," says Ming Zhao, an environmental engineering professor at Tsinghua University in Beijing. Teams are actively working to improve this process, knowing that breakthroughs here unlock the whole chain.

Meanwhile, researchers at the University of Illinois tackled a more specific problem: turning food waste — which makes up the largest share of trash in many cities — into usable jet fuel. They tested dozens of chemical catalysts and found one containing cobalt and molybdenum that works in a single step, refining food-waste biocrude into jet fuel that meets current aviation standards without needing to blend it with conventional fuel. This is the first time food-waste-based jet fuel has achieved that directly.

The same process could also produce gasoline and diesel, expanding the potential uses. But here's the honest part: waste alone won't solve aviation's fuel problem. Even if we converted every scrap of trash on Earth into jet fuel, we'd still need other solutions — better aircraft design, fewer flights, or eventually new propulsion systems. What waste-based SAFs do offer is a meaningful piece of the puzzle, turning something we already discard into something the aviation industry desperately needs.

The technology is moving from theory into real production. As gasification improves and these catalytic processes become more reliable, the first trash-powered flights aren't a distant dream — they're becoming an engineering problem with a clear path to solving it.