Science, Tech & Environment

Desert lunch: Coaxing climate-friendly food from the world's driest places

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Credit: Sahara Forest Project
An artist’'s rendering of a full-scale commercial low-input desert agriculture facility. Project’s designers say the concept should work in any low-altitude desert area near a large source of salt water.

In Qatar, a team of scientists and engineers has set out to prove that people in the world’s most inhospitable places can transform sunlight, salt water and CO2 into energy, fresh water and food. Jon Miller reports as part of our series “What’s for Lunch."

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You would be forgiven if you were to visit the pilot site of the Sahara Forest Project, in an industrial zone south of Doha, and the word “bucolic” didn’t spring to your lips. It looks like an outpost on Mars—an array of trailers and fences and pipes and tanks and mirrors and concrete slabs, all baking on a rectangle of sand. Behind it looms a gigantic fertilizer factory, spitting orange fire, spewing clouds of ammonia, roaring like a furnace.

But, if you look closely, you can see life. In fact you can taste it, in the form of a perfect baby cucumber, from an early test crop grown without soil in a gleaming glass greenhouse that could be pretty much anywhere.

What’s different, says the project’s research director, Virginia Corless, is the way the greenhouse maintains a comfortable environment for plants.

For one thing, she says, the air is enriched with carbon dioxide piped in from the fertilizer factory next door. The cooling system is also different. Rather than using traditional, energy-intensive air conditioning, this greenhouse keeps cool by evaporating seawater.

As the water evaporates, Corless says, “according to basic physics, the air becomes cooler and more humid, and it’s a great place for the plants to grow.”

Corless knows a thing or two about physics. She has a degree in it from MIT. For her Ph.D. at Cambridge University in England she studied dark matter in distant galaxies. Now, at age 30, her concerns are more earthly.

She says the pilot facility is the first experiment in integrating technologies to produce food, fresh water and clean energy in deserts using seawater. “And if you look at the crises the world is facing, we need all of those things really badly,” Corless says.

The vision for the Sahara Forest Project—sahara means “desert” in Arabic—was provided by a pair of Brits, architect Michael Pawlyn and engineer Bill Watts. The two were interested in designing facilities that mimic natural ecosystems, where the waste from one component is the food or fuel for another.

Joakim Hauge was working as an ecologist in Norway when he heard about their plan to green up the deserts of North Africa and the Middle East. Now the project’s CEO, Hauge says the team didn’t start with the technologies.

“We started with a thought, and that was, let’s take what we have enough of, like seawater, like sunlight, like sand, like CO2, to produce what we need more of—food, water, energy—in an environmentally friendly way.”

This two-and-a-half-acre pilot facility was built to test that idea under real-world conditions. It’s here in Qatar because the emirate has that sunlight, seawater, sand, and C02—as well as lots of money.

The seawater, pumped from the nearby Persian Gulf, is the system’s lifeblood. It’s used to cool and humidify the greenhouses. It’s also used to grow algae to produce biofuel, with the leftovers from that process going to make animal feed. Some of it is transformed into fresh water by a solar-powered desalination unit. Some of it may even be used down the road to raise fish or shrimp.

The core innovation, Corless says, is the integration of technologies. “While many of the individual technologies have been developed elsewhere in the world, they’ve never been brought together in this way. And integration is not easy. But the benefits to the added complexity we think are well worth the extra effort.”

The main benefit, at least in theory, is efficiency. As in nature, almost everything is recycled. And the energy to run it comes from the sun. In fact, Corless expects that a full-sized commercial facility would consume more CO2 than it produces.

Corless’s favorite experiment on the site is a desert nursery, where she and her colleagues are testing a variety of native desert species to see which have the potential to be cultivated agriculturally. It’s low-tech, but she says it’s one of the most important for tipping the carbon balance.

The nursery looks sort of like a beach volleyball court, except with open-cell cardboard walls that are dripping with seawater. It uses the same principle as the greenhouse, only the water here is evaporated by the wind instead of a fan. The hope is that the cooler, moister air will help grasses, shrubs and trees take root and eventually spread on their own into the desert. Hence the name—the Sahara Forest Project.

So far, Corless says, the only surprise is how well the plants have grown.

The bigger question is whether the whole system will take root and grow and spread.

Corless says she and her colleagues would be happy to see the concept being applied all over the world, and not just by themselves. She says it has the potential to open up “a whole set of regions in the world, desert areas, to a new kind of agriculture and energy generation in a way that can really have a global impact.”

But it’s a long way from here to there.

To be financially viable, a facility needs to be big. That takes serious money—not a problem here in Qatar, but plans to build a site in Jordan have moved much more slowly. Then there’s the business model—designing and building complex facilities in harsh environments, then recouping the cost by selling vegetables, electricity, fuel, animal feed, water, salt, maybe fish, maybe fruit, maybe fodder.

It’s a lot to get right, and a lot to go wrong. Nature is a terrific model. It’s also the product of eons of trial and error.


What’s for Lunch” is the latest chapter in “Food for 9 Billion,” a two-year project spearheaded by Homelands Productions and the Center for Investigative Reporting, and broadcast partners PBS NewsHour and American Public Media's Marketplace.

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