Deserts as carbon sinks? Study reveals potential for greening arid regions

In a recent opinion paper, a team of plant scientists has introduced a novel method to sequester carbon dioxide by “re-greening” arid regions, without competing with agriculture or food production.

This innovative solution was proposed by a research team led by Heribert Hirt from the King Abdullah University of Science and Technology.

Their report, published in the journal Trends in Plant Science, suggests that deserts could be transformed into carbon sinks.

The climate challenge

As carbon dioxide (CO2) levels rise, the race is on to find solutions beyond merely cutting emissions. 

“With greenhouse gas (GHG) concentrations at the highest level for 2 million years, humanity is facing an unprecedented challenge from climate change,” wrote the researchers.

“Consequently, average temperature increases, ice sheet melting, ocean/sea level increases, and extreme weather patterns are becoming routine. These changes threaten the foundations of human civilization.”

Capturing and storing vast amounts of CO2 already in the atmosphere has become crucial. Reforestation is considered to be an ideal approach, but often clashes with agricultural needs.

Turning deserts into carbon sinks

The researchers propose that we could transform arid ecosystems into efficient carbon-capture systems with improved soil health, enhanced photosynthetic efficiency, and larger root biomass by engineering ideal combinations of plants, soil microbes, and soil type.

“Re-greening deserts by restoration of ecosystem functions, including carbon sequestration, should be the preferential approach,” wrote the researchers. 

“The advantage of reclaiming arid regions for re-greening and carbon sequestration is that they do not compete with lands used in agriculture and food production.”

Arid regions

Arid regions cover approximately one-third of our planet’s land surface. These areas typically support minimal vegetation due to water scarcity. 

Yet, certain plants, adapted to these harsh conditions, have evolved ways to survive. 

Some use unique photosynthesis methods, others have special root systems, and a few even produce oxalates which can convert into water during droughts.

The oxalate-carbonate pathway

Oxalates are ions made up of carbon and oxygen. Soil microbes consume these oxalates as their primary carbon source. 

Upon doing so, they release carbonate molecules into the soil. These molecules can react with calcium in calcium-rich and alkaline soils, forming stable calcium carbonate deposits.

This biogeochemical process can be enhanced in arid lands to transform them from barren stretches into thriving carbon sinks, complete with healthy soils and plants. 

“Overall, in this form of carbon sequestration, one out of every sixteen photosynthetically fixed carbon atoms might be sequestered into carbonates,” wrote the study authors.

Fertility islands

To initiate this transformation, the authors propose the creation of “fertility islands.” 

These are small pockets of revived habitat where plants and microbes can flourish and eventually spread, creating a blanket of vegetation across the arid landscape.

Challenges and future directions

Despite its promise, this method also has some challenges. Arid conditions naturally mean slower plant growth, which could limit the pace of carbon sequestration. 

Additionally, the adoption and effectiveness of this technology rely heavily on the financial and political will of countries with arid regions.

Study implications 

As the global community searches for ways to tackle the impending climate crisis, re-greening arid lands could offer a solution. 

Not only could this method sequester vast amounts of carbon, but it could also restore ecosystems, bringing life back to some of the most barren places on Earth.

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

—-

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.