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Synthetic fats made from only water and air could be environmentally transformative

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Synthetic fats made from only water and air could be environmentally transformative

Substitutes for palm oil and soy could divert gigatons of CO2 and spare millions of hectares of habitat lost to agriculture
November 10, 2023

Let the best of Anthropocene come to you.

Consider a scoop of ice cream: part of what makes this dessert so delicious is palm oil, a product that comes from vast plantations, which have been linked to millions of hectares of deforestation and biodiversity loss. Such devastation in the name of nutritionally-unimportant foods such as ice cream—or biscuits, crisps, and pizza dough, which also contain palm oil—seems like a travesty. 

But now a new review suggests that exciting advances in food tech could enable us to make molecularly-identical fats, without any farmland or crops, and near zero emissions.

This isn’t as futuristic as it may sound, the new Nature Sustainability study says: we’ve actually been manufacturing edibles from non-agricultural feedstocks for decades, including a margarine made from coal in the 1940s. 

This seemingly alien technology actually depends on the same raw materials as in photosynthesis: hydrogen from water, plus carbon. In place of photosynthesis, artificial methods of fat production use a series of chemical reactions that can make fats quickly and at scale. 

One example that’s used today is similar to the process used to make ‘coal butter’ during the Second World War. Burned coal is transformed with gasification into a synthetic gas (syngas), which is a mixture of carbon monoxide and hydrogen. Then, through a chemical process called the Fischer-Tropsch reaction, the syngas is transformed into paraffins, and that’s oxidized to release fatty acids. Syngas could also be derived from less polluting sources, like organic biomass and municipal waste, or carbon captured from the air. 

 

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In the study, the researchers analyzed the lifecycle energy use, emissions, and water use of these and other methods of artificial fat generation that currently exist. Then they compared these to the lifecycle impacts of palm and soybean production for dietary fats.

These impacts were calculated right from the point of fossil fuel extraction as potential feedstock for artificial fats, to the land-use emissions associated with deforestation and fertilizer to grow oil crops. 

And when the results came out, artificial fats undoubtedly had the lower footprint. The environmental benefits of these synthetic foods were striking, in fact: the researchers calculate that while soy and palm oil produce between one and three grams of carbon dioxide emissions for every Calorie, artificial fats produced from feedstocks like syngas produce less than a gram. 

And, if artificial fats were produced using carbon dioxide extracted from the air (instead of derived from a fossil fuel source), and the production process was powered by renewable energy, that amount plummets to almost zero emissions.

To put this into context, the researchers calculate that if we had already taken steps to replace palm oil with synthetic fats, in palm-oil intensive Malaysia alone, this would have so far diverted over a gigaton of carbon dioxide equivalent emissions, and saved 100 million hectares of tropical habitat, according to agricultural figures from 2017.

Beyond emissions and land-use, synthetic fats would also require between 100 and 800 times less water than their agricultural counterparts. 

With such impressive figures, synthetic fats are surely a no-brainer—so why don’t we turf palm oil for fats formed from air and renewable energy alone? 

For now, widespread adoption of artificial fats doesn’t quite match the complex reality. There are questions around the cost of the technologies that would make synthetic fat possible at scale. The researchers also point out that for this technology to operate at its optimal low-emissions rate, we will need advances in carbon-removal tech so that the raw materials can be sucked from the air, and decoupled from fossil fuels entirely. 

But perhaps the largest challenge is the huge socioeconomic importance of industries like palm oil agriculture, which directly employs 6 million people worldwide.

The study notes that smaller agricultural sectors track with countries that have more prosperous economies, and so artificial fats could be a key driver in this downsizing process, with benefits for both environment and economy, perhaps. Even so, any movement away from intensive palm oil monoculture would have to involve a just transition for its enormous workforce, the authors stress—a massive challenge for which we have no clear boilerplate yet. 

The question is whether the environmental gains of synthetic fats could be worth this uncertainty. To find out, substituting the fats in highly processed, unnecessary snack foods would be the most sensible place to start, the authors suggest: “Folks may be less concerned about what kind of fat is in a store-bought cookie or pie crust because they don’t know what’s in there right now.”

Davis et. al. “Food without agriculture.” Nature Sustainability. 2023. 

Image: Envato Elements

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