The controversial plan to turn a desert green

A team of engineers and ecologists have a plan to turn Egypt's Sinai Peninsula green. (Tim Peake/ESA/NASA via Getty Images via CNN Newsource)

Ties van der Hoeven’s ambitions are nothing if not grand. The Dutch engineer wants to transform a huge stretch of inhospitable desert into green, fertile land teeming with wildlife.

His sights are set on Egypt’s Sinai Peninsula, an arid, triangle-shaped expanse that connects Africa with Asia. Thousands of years ago it was bursting with life, he said, but years of farming and other human activity have helped turn it into a barren desert.

Van der Hoeven is convinced he can bring it back to life.

He has spent years fine tuning an initiative aimed at restoring plant and animal life to roughly 13,500 square miles of the Sinai Peninsula, an area slightly bigger than the state of Maryland. The goal: to suck up planet-heating carbon dioxide, increase rainfall and bring food and jobs to local people.

He believes it is the answer to a slew of huge global problems. “We are destroying our planet in a way which is scary,” he told CNN. “The only holistic way out of this situation is with large-scale ecological regeneration”

So-called desert regreening projects are not new, and this is one of a number around the world seeking to transform arid landscapes. Many aim to halt desertification — the creeping degradation of dry lands — a phenomenon the United Nations calls a “silent, invisible crisis that is destabilizing communities on a global scale.”

But the concept is also controversial; critics say transforming deserts is unproven, enormously complex and could negatively affect water and weather in ways we cannot predict.

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The birth of the plan

Van der Hoeven’s background may seem unlikely for someone intent on saving the world. As a hydraulic engineer at Belgian dredging company DEME, he worked on projects including building artificial islands in Dubai.

But in 2016, the course of his career changed when he was pulled into a venture to help the Egyptian government restore shrinking fish populations in Lake Bardawil, a saltwater lagoon in northern Sinai, separated from the Mediterranean by a narrow sandbar. It used to be more than 100 feet deep but is now less than 10 feet deep in parts, as well as hot and salty.

Within a few weeks, van der Hoeven devised a plan to open up the lagoon by creating tidal inlets and dredging “tidal gullies” to get more seawater flowing through, making it deeper, cooler, less salty and more full of marine life.

But the more he researched, the bigger he wanted to go.

Scanning the terrain in Google Earth, he saw the outline of a network of now dried-up rivers, criss-crossing the Sinai like blood vessels, suggesting this land was once green. He pored over weather models and ecological studies and started to see connections.

He could use the sediments dredged from Lake Bardawil to help regreen the surrounding area. “They are salty but they hold very many nutrients and minerals, which you need to start restoring the land,” he said.

He would start with the wetlands around the lake, expanding them to lure the birds and fish.

Then, he would go higher into the region’s mountains, pumping in the lake’s sediments and layering them to create soils where they could grow different varieties of salt-tolerant plants. These would help revitalize the soils, van der Hoeven said, reducing salt levels and making the land able to support a larger array of plants.

Van der Hoeven’s central idea is that adding vegetation to the landscape will mean more evaporation, more clouds forming and more rain falling. It could even change the winds, as greening the region can bring back moisture-laden flows of air, he said.

“This could completely change the weather patterns.”

None of this will be quick.

Van der Hoeven estimates it will take five to seven years to fully revitalize the lake, then between 20 and 40 for the wider regreening.

“It’s really nature telling us the speed,” he said.

Restoration 'on a planetary scale'

Van der Hoeven’s idea might sound wildly ambitious, but it’s been done before.

As he was feverishly planning the Sinai project, he came across the film “Green Gold,” made by cameraman-turned-ecologist John Liu, which documents a huge desert regreening project in the Loess Plateau in northern China.

The region, nearly the size of California, had been heavily degraded by years of overuse and overgrazing. With sparse vegetation and covered in thin, ocher-yellow soil, it was very prone to erosion.

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In an attempt to transform the land, China’s government and the World Bank launched a large-scale regreening program in the 1990s, planting trees and shrubs and implementing grazing bans.

In the decades since, the Loess Plateau has flourished. Parts of the land are now carpeted in green, soil erosion has reduced and less sediment flows into the region’s Yellow River, lowering the flood risks.

The Loess Plateau in Gansu Province, China in 1993. (Wolfgang Kaehler/LightRocket/Getty Images via CNN Newsource)Green mountains and the blue-green waters of the Yellow River on the Loess Plateau in Yongjing, Gansu province, China, on July 24. (Costfoto/NurPhoto/Getty Images via CNN Newsource)

For van der Hoeven, it was further proof his plan could work.

He sought out Liu, who was immediately on board. The idea of regreening what was once a “land of milk and honey” was “extremely exciting,” Liu told CNN. “The scale reaches a level that helps prove that restoration can be done on a planetary scale."

It would add to other huge desert regreening projects also underway.

The Great Green Wall in Africa, for example, was launched in 2007 to help combat desertification.

Originally intended to be a belt of trees planted for thousands of miles across the continent’s Sahel region, the initiative has morphed into a “a mosaic of green and productive landscapes” over 11 countries, said Susan Gardner, director of the ecosystems division at the UN Environment Programme in Nairobi.

Restoration efforts are essential for tackling the climate crisis, nature loss and pollution, Gardner told CNN. “We don’t have a choice. We have to do this; we have to listen to the science and act now.”

A 'flashy distraction?'

But ecosystems are incredibly complex and when it comes to huge, transformative projects like regreening a desert, some experts are concerned about unintended consequences.

In a project’s quest for a successful finish line, there is a risk that it will opt for fast-growing, non-native species which either don’t survive or become invasive, overtaking the surrounding native plants and damaging wildlife, said Alice Hughes, an assistant professor at Hong Kong University’s School of Biological Sciences. Others are water-thirsty, which can cause conflict with people’s needs.

During the early stages of Africa’s Great Green Wall project, many of the trees died for lack of water, neglect or because they weren’t suitable for the land.

Even in the Loess Plateau, widely credited as an astonishing success, there is evidence the vegetation may be approaching, or even exceeding, what the local water supply can support.

A 2020 study of the region found that higher levels of evaporation from trees and plants had little impact in terms of increasing rainfall, and even led to “lower water availability for agriculture or other human demands.”

Changing the ecosystem could also mean “potentially changing climate patterns, which may reduce moisture and drive droughts elsewhere,” Hughes said. Evaporation may cool one place but simply deposit the heat in other places.

Planting vegetation could even end up having a warming effect. Light-colored deserts can reflect more of the sun’s energy back into space than darker vegetation. “Deserts actually cool the planet,” said Raymond Pierrehumbert, a physics professor at the University of Oxford.

While regreening arid places could bring local cooling effects, Pierrehumbert told CNN, they could end up “leaving the rest of the planet worse off.”

“We also need to ask ourselves why we are doing it,” Hughes said. These projects can act as “flashy distractions,” she added. “They sound much more exciting than the basic work of protecting existing intact systems, which are still vanishing at astonishing rates.”

For Liu, however, there is a big difference between natural deserts and those humans helped create. The argument human-caused deserts should not be touched — even those that have been around for thousands of years — “does not seem logical to me,” he said.

Van der Heoven readily admits the project is complex but believes it’s vital to try. “We should protect nature with all we have, but we should also restore nature with all we have,” he said.

He is studying exactly which plants will be able to attract wildlife and survive future climate change impacts. He also believes changing the climate in the Sinai Peninsula will have a positive ripple effect for the region.

Perhaps one of the biggest obstacles for now is regional instability as the war in Gaza continues.

At the end of 2022, the Egyptian government signed an agreement to start researching and planning the restoration of Lake Bardawil. The project was scheduled to kick off this December, but conflict has slowed everything down, van der Hoeven said.

He’s still confident it will happen and thinks the current situation “creates an even stronger case” for regreening as a way to help bring more opportunity and prosperity.

What is clear is that climate change and biodiversity loss, two interlinked global crises, are getting worse, and in the scramble to solve them, the idea of regreening arid land is gaining currency.

As with many compelling, moonshot ideas to tackle huge, complex problems, there are those who urge caution and warn of the dangerous consequences of rushing in, and there are those who argue the situation is now so urgent, there is no choice but to try them.

Van der Hoeven is firmly in the latter camp.

Regeneration of the natural world “is the only way out of the mess we are currently in,” he said. “There is no time anymore not to act. We should act and accept that we don’t know everything.”