We all depend on our environments.

Yet, in living memory, our environments have become drastically degraded. Climate change and human activities are rapidly affecting our lands, often leading to the propulsion of vicious cycles or, in scientific terms, positive feedback loops. Desertification – the turning of biologically productive land into desert – is one result of such a form of environmental degradation.

Earth is drying up rapidly. Just over 40 percent of the planet’s ice-free land surface is considered drylands, areas adapted to face water scarcity; but they are vulnerable to damaging human activities and subsequently subject to desertification. According to the UN, worldwide, 12 million hectares of land is lost to desertification and drought every year – which works out to be 23 hectares a minute – and a growing 1.5 billion people depend on degraded land globally. The UN estimates that by 2032, 50 million people will be displaced due to desertification.

As well as the growing number of climate refugees, desertification causes water and food scarcity, poverty, biodiversity loss and increased natural disasters. It is changing the shape of communities and influencing shifts in traditional cultures as people are forced to adapt to survive.

This all sounds very bleak. The statistics certainly don’t paint a pretty picture. But we can create and participate in a global vision to mitigate and adapt to climate change
and environmental degradation.

Now is the decade of doing – the decade of action. We must rise to the call to accelerate sustainable solutions to the world’s biggest challenges. And many are heeding this call.
But how do we tackle a challenge so large as climate change? The solutions are many, but one is to break a feedback loop that drives desertification by regreening desertified lands.

Let’s take a look at the science, simplified. The water cycle relies on evapotranspiration, the combined process of water evaporating from the soil’s surface and water vapour being expelled (transpired) by leaves on trees and plants. Evapotranspiration accounts for around 15 percent of the water vapour in our atmosphere, without which clouds couldn’t form and rain wouldn’t fall. When the plant cover is lost from the land – perhaps from deforestation, overgrazing or urban expansion – we also lose the associated transpiration; and when the land is so dry that water no longer seeps into the soil, we lose the associated evaporation. And then we lose the rain, and, subsequently, plants die and the land dries further. And on it goes.

When areas are regreened, the process of evapotranspiration can restart. And when this happens over many sites covering a large area, the compound effect is a positive influence on the local and regional water cycle and rainfall. Turning bare soil into vegetated areas allows the water to soak into the land rather than rush off it, reducing soil erosion and the likelihood of flooding. It also creates a cooling effect, decreasing the heat transfer from the land’s surface into the atmosphere, subsequently influencing local meteorology and, in many cases, welcoming rain. With the land covered in vegetation, soils can recover and organic matter can begin to build up, with rippling positive impacts.

Desertification is happening in drylands across the planet. It is an issue that countries on every continent are facing. But simple- to-implement, nature-based solutions driven through community action can turn the tide on desertification and positively affect the climate regionally and globally. The impacts could be enormous, moving millions of people away from vulnerability and insecurity and transforming depleted land into land thriving with life.

Sources: International Union for the Conservation of Nature’s “Issues Brief: Drylands and Land Degradation”, June 2017; and the United Nations Convention to Combat Desertification.