January 29, 2016Soil Written by Greentumble Editorial Team
has brought an end to many majestic civilizations throughout human history and continues to threaten the existence of 1.5 billion people until the present day¹. Desertification is the process by which fertile land is transformed into desert as it becomes progressively drier and unable to support any plant growth for food production. One third of the land surface on Earth has fallen victim to desertification¹ and according to the estimates, it claims 12 million hectares (approx. 30 million acres) more every year². For comparison, it is the same size like the area of New York State turning in desert just within a year³.
Desertification is having major impact in many places on our planet today, and is expected to affect humanity even more in the future as we experience an increase in human population, and as our planet faces scarcity of natural resources such as clean water. The process happens due to a number of reasons, but much of the desertification that is occurring around the world today is caused by human activity on lands that are extremely vulnerable to overexploitation and improper agricultural methods.
The following are some of the primary causes and effects of desertification in our world.
Causes of desertification
In arid regions, grass and other vegetation is necessary to keep the soil in place. If the vegetation is overgrazed by livestock, there is nothing that remains to prevent soil from blowing or washing away, and if this process occurs long enough, it can lead to desertification.
Forests are being cut down at much larger scale than ever before to be used as fuel, to provide products we use in our daily life, or to simply create more space for agriculture to sustain growing human population. Once the trees and other vegetation in an area are gone, there is nothing left to hold the soil in place. The soil then turns to dust and can be blown and washed away, and the soil is degraded and the precious soil nutrients are lost, leaving the soil infertile and useless.
Unsustainable agriculture techniques
Improper irrigation methods used in arid areas, such as canal irrigation, lead to a buildup of salt in the soil and make it difficult for crops and other plants to grow, increasing desertification. Similarly harmful is cultivation of already deteriorated lands. Through inconsiderate farming methods, farmers only speed up the process of desertification in exchange for poor quality crops with low economic value. Besides, while preparing the soil for sowing, natural vegetation that holds the soil in place is removed, leaving land more vulnerable to degradation.
Our planet’s ecosystems sustain life only when balanced. They can cope with incremental challenges and adapt but beyond a certain tipping point they collapse. A rapid increase in human population demands higher amounts of natural resources and expands more and more over the landscape, leading to increased desertification.
As humans continue to remove vegetation from landscapes, there is less remaining vegetation to add moisture to the soil that will evaporate into the air and form clouds that lead to rainfall. With significantly reduced rainfall, drought occurs and leads to a hotter and drier climate, and later causes desertification in the surrounding landscape.
Famine, poverty and political instability
While desertification certainly leads to these problems, they can also be a cause of desertification. This is because people on the brink of famine, extreme poverty or political instability in their country need to solve the crisis at the moment and do not think about sustainable cultivation strategies. Unfortunately, the outcome are poor land use practices such as keeping too many animals in a small pen and unsustainable short-term food production, which might destroy soils beyond repair, and put lives of people even more in danger.
Effects of desertification
The soil becomes infertile
As desertification occurs, the soil can be blown or washed away, and valuable soil nutrients are lost. Through the use of unsustainable irrigation techniques, salt can also build up in the soil, rendering the soil useless for growing crops or other plants. As the soil dries out, it hardens and it becomes difficult for any rainfall that does occur to penetrate below the soil’s surface. And what remains left is a lifeless pile of dust instead of a life-giving medium.
Vegetation is damaged or destroyed
Desertification reduces the ability of land to support plant life. Loose soil bury plants, or their roots become exposed and cannot fulfill their function. With plants dying, rainwater gets washed away instead of being drawn into the soil, which only scales up the problem as remaining plants do not have enough moisture to survive dry spells as they used to.
Additionally, if the land is used for grazing at this stage, it only results in a quicker loss of plant species and total degradation.
The reduction in plant cover increases the erosion of the soil due to increased runoff and direct exposure to wind. This results in the decrease of water storing capacity of soils. The process of desertification is worsened as the soil becomes increasingly arid, and there are no more plants to hold it in place and distribute nutrients. Soil erosion is the final step that closes the loop of continual soil deterioration that is impossible to revert.
Desertification makes natural disasters worse. Events such as flooding, dust storms, and pollution, all become stronger in areas with heavily degraded soils. Without any plants stabilizing the soil and slowing down the runoff, rainwater easily accumulates and floods human settlements in the blink of an eye.
Except causing damage, flood water also picks up unwanted pollutants while making its progress through urban areas, and that’s how pollution spreads over vast areas.
Polluted sources of drinking water
Vegetation plays an important role in cleaning our water. Plants and trees function like natural filters, storing pollutants such as heavy metals from water in their own bodies. Barren soils lack this green filter, and therefore, more of these harmful substances enter our groundwater reservoirs.
Famine, poverty, and starvation
Due to drought conditions and a loss of productive land, local people find themselves experiencing famine and poverty, as well as potentially the starvation of themselves and their livestock.
Collapse of civilizations
There are many historical accounts of how various people groups throughout human history experienced collapse of their civilization as drought and desertification occurred to their lands. These accounts include the Carthage Civilization, the Harappan Civilization, people groups in Ancient Greece, the Roman Empire, and people groups in Ancient China⁴.
Desertification events have been a major driver behind the migration of large human populations throughout history. When soils are not able to support their civilization, people set on the move to look for better locations. One historical record of such a migration are Sea Peoples who during the Bronze age sailed their ships to Egypt, Syria and Cyprus most likely from Southern European countries⁵.
Species that once lived in a fertile and productive climate may not survive in a newly desertified region. With a changing ecosystem, species must adapt to their new climate or migrate to a more favorable climate. Unfortunately, some of them also become extinct for their inability to cope with a sudden change of their environment.
This list of causes and effects of desertification is just a brief fraction of the whole scope of such an extensive problem taking place on our lands every day. Majority of those who are affected the most by this problem are as usual the world’s poorest nations, where people struggle daily with the direct impacts of climate turning against them, and deserts claim more of their already scarce soils. Therefore, it is important to realize after reading this article how valuable soil conservation is. And try to do everything in our power to help protect natural resources we have.