On the World Day to Combat Desertification, DW asks what the commonly used term actually means, why it is such a problem in so many parts of the world, and what can be done to reverse it.
What is desertification?
The United Nations Convention to Combat Desertification (UNCCD) defines it as “land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities.” Boil that down to its essence, no pun intented, and what you have is the process of drylands becoming a bonefide desert. Since more than a quarter of the world's population live in dry areas, desertification has a significant impact not only on biodiversity and the very climate that helps drives it, but also on socio-economic stability.
What causes desertification?
Although deserts have always grown and shrunk in time with naturally occurring phenomena like gradual changes in climate, the human hand has played a major role in the dramatic desertification found in many parts of the world today. By way of example, when people who live in drylands on the edges of deserts exhaust their limited vegetation in order to feed their livestock and their fires, they throw their delicate ecosystems out of whack. As a consequence, drylands can become deserts. But that is by no means the only reason for the drying out of much of our world. Global climate change has cast its long shadow over delicate ground, bringing shifting weather patterns and longer periods of drought that facilitate the spread of aridity.
Excessive exploitation of the soil, for grazing, for example, can destroy the vegetative cover and lead to soil erosion
Who is affected by desertification?
Desertification is a phenomenon that occurs on all continents, except Antarctica. That said, 72 percent of all dryland in the world is in developing countries, which means a staggering 90 percent of those affected live in poorer regions. Within affected countries, it is some of the poorest communities that suffer, which makes desertification a major obstacle to development and the fight against extreme poverty. Equally, desertification can affect people who live nowhere near drylands or deserts. Massive dust clouds, for example, are becoming increasingly common. Those, which originate in Mongolia - a candidate for rapid desertification - have been known to travel as far as the US before finally breaking apart. This phenomenon has proved fatal in those with respiratory problems, and wreaks untold havoc in distant places.
Desertification may not be a new phenomenon
Humans have been meddling with their environment for thousands of years and there are some indications that man-made desertification may not be an entirely new phenomenon. Some historical research suggests that mismanagement of natural resources may have significantly impacted a variety of ancient cultures - such as Rome, Greece and Carthage - by drying out lands on which they once flourished. Even if that were the case, and there is some dispute, the effects would not have been as widespread as they are today.
What can be done to combat desertification?
Prevention, as they say, is better than a cure. That is particularly true of desertification. And it is cheaper too. An important step is to limit the likelihood of soil erosion by ensuring vegetation doesn’t disappear. One way to achieve this is to alternate between using land for farming and grazing as opposed to limiting it to one or the other. If done right, this puts less stress on the soil and maintains a natural cycle of nutrients. It is also important to manage land and water resources jointly to prevent erosion and salinization.