My Eco Talk Six

How to Green the World’s Deserts and Reverse Climate Change

Allan Savory takes us through how we can turn the world’s deserts green and reverse climate change.

The most massive tsunami, a perfect storm, is bearing down upon us; it is the result of a growing population of 10 billion people, land turning to desert (desertification) and climate change.

There are environments where humidity is guaranteed throughout the year, and environments with months of humidity and months of dryness. It is in the latter where desertification is occurring. Fortunately, with space technology, we can look at these environments. About two-thirds of the world is going through the process of desertification.

In the Tihaman Desert, Savory was astounded when 25 mm of rainwater fell, but the next day, the land was totally dry. So, where did the water go? Some of the water runoff is flooding, however most of the water soaked into the soil and then evaporated out again. 

Because the fate of water and carbon are tied to soil organic matter, when we damage soils, carbon leaves the ground and goes back to the atmosphere.

While desertification is known to occur in arid and semi-arid areas, sometimes uncovered soil in high rainfall areas leads to increased run-off and evaporation, and thereby desertification occurs. However we do not recognize this until it reaches its terminal form. We also know that desertification is caused by livestock overgrazing the plants, which leaves the soil bare, giving off methane.

Savory grew up in Africa where he developed a hatred of the local livestock due to the damage they were doing to the environment; a belief further enhanced by his university studies in ecology. He decided to reduce the number of elephants in the area to a level, he believed, the land could sustain. Tragically, in the following years, 40,000 elephants were killed to put a stop to the damage, but the situation never actually improved. 

Savory, a elephant lover, was deeply affected by this situation, and he became determined to devote his life to finding solutions.

Coming to the US, he found out that national parks were changing just like in Africa, they were becoming arid and turning into deserts, despite no livestock having grazed on them for decades. Scientists had no answer as to why this was – for them it was natural. Savory decided to start researching into this problem, looking at land that has dersertified for no apparent reason. 

We have never truly understood what is causing desertification across the globe, causing many civilizations to suffer and threatening us globally. We had not understood, that the seasonal humidity in environments across the world, as well as the soil and the vegetation, developed with the grazing of large numbers of animals. These animals had to defend themselves against aggressive predators; their main defense being existing in large herds to keep individuals safe. These herds would keep moving continually as another defense method which in turn kept plants from being overgrazed and their trampling ensures that the soil is covered at all times. Their dung would also fertilize the soil and enrich it for future plant growth. 

Plant cover like grass, decays biologically. If it doesn’t, it decays through oxidation, a slow process that leads to woody vegetation and bare soil, which also leads to carbon emissions. Fire is also used to clear land, which again leaves the land bare and releases carbon. Burning 1 hectare of land gives off more damaging pollutants than the emissions of 6,000 cars. Fire clearance is justified by scientists because the land is cleared of dead material and allows plants to grow; it is however not a sustainable solution. 

To keep most of the world’s lands healthy and reducing plants numbers is not a choice. So what are we going to do?

The only option is to use livestock, mimicking the natural movement and behaviour of herds which is so beneficial to the plants, ground cover and soil; preventing desertification.