Greenhouse gases from cars and planes could one day be drastically reduced. In a new study published in the Proceedings of the National Academy of Sciences, a team of scientists from the University of California at Berkeley outlined a new method for creating jet fuel and diesel that doesn’t require burning any fossil fuels. Instead, it uses only sugar factory waste.

The research team, led by Alexis Bell, figured out how to create fuels that produce only a fifth of the greenhouse gases that burning standard fossil fuels or ethanol-based biofuels would produce. “All of the carbon and any hydrogen required for the fuel are derived from biomass, rather than fossil fuels,” Bell tells Quartz.

Some of the most expensive ingredients in creating ethanol out of sugar, Bell says, are the enzymes required to break down sugarcane’s cell walls. While effective, these enzymes are needed in large quantities and manufacturing them is costly.

Bell’s team instead used hot water along with a cheaper, renewable catalyst. A catalyst is a substance that gets a reaction going without directly participating in it. For this reason, only tiny quantities of a catalyst are necessary. (For the nerds, the catalysts are magnesium oxide and niobium pentoxide.)

Hot-water treatment is usually used to separate sugar from sugarcane anyway. Bell’s method takes one extra step, employing renewable catalysts to convert the leftover sugarcane biomass into fuel.

The process is simple. First, fermentation breaks down the biomass into chemicals containing only a handful of carbon atoms, such as in ethanol, acetone, or butanol. Next, Bell’s catalyst kicks off a chemical reaction that joins up smaller molecules to make chemicals that are comprised of longer chains of carbon atoms that can be used as diesel, jet fuel, or a lubricant.

Bell says burning this fuel puts no additional burden on to the environment, because the carbon comes from plants, rather than fossils that were dug up, burned, and added to the atmosphere. “It’s a closed loop,” he says.

But it’s unlikely that oil companies are going to be dismantling their rigs any time soon. This work is still in the research phase, and it’s uncertain how cost-effective it would be to make fuel from sugarcane on a large scale.

The team’s work, Bell says, is sponsored by BP, which has large sugarcane plantations in Brazil that produce ethanol for flex-fuel cars. While Bell can’t confirm the economic viability of his team’s fuel, he says that BP were encouraged enough by what they saw to keep funding the research. BP was not immediately available for comment on its involvement in the research.