What is Desertification?
Desertification is the persistent degradation of dryland ecosystems by variations in climate and human activities. Home to a third of the human population in 2000, drylands occupy nearly half of Earth's land area. Across the world, desertification affects the livelihoods of millions of people who rely on the benefits that dryland ecosystems can provide. In drylands, water scarcity limits the production of crops, forage, wood, and other services ecosystems provide to humans. Drylands are therefore highly vulnerable to increases in human pressures and climatic variability, especially sub-Saharan and Central Asian drylands. Some 10 to 20% of drylands are already degraded, and ongoing desertification threatens the world's poorest populations and the prospects of poverty reduction. Therefore, desertification is one of the greatest environmental challenges today and a major barrier to meeting basic human needs in drylands. Desertification affects the world's most vulnerable populations. How are desertification and human well-being linked? In drylands, more people depend on ecosystem services for their basic needs Desertification affects a wide range of services provided by ecosystems to than in any other ecosystem. Indeed, many of their resources, such as crops, humans: products such as food and water, natural processes such as livestock, fuel wood, and construction materials, depend on the growth of climate regulation, but also non-material services such as recreation, and plants, which in turn depends on water availability and climate conditions. Supporting services such as soil conservation. Changes can be quantified and methods are available to prevent, reduce, or reverse them. Fluctuations in the services supplied by ecosystems are normal, especially in drylands, where water supply is irregular and scarce. When faced with desertification, people often respond by making use of However, when a dryland ecosystem is no longer capable to recover from land that is even less productive, transforming pieces of rangeland into previous pressures, a downward spiral of desertification may follow, cultivated land, or moving towards cities or even to other countries. This though it is not inevitable. can lead to unsustainable agricultural practices, further land degradation, exacerbated urban sprawl, and socio-political problems. Who is affected by desertification? Desertification affects the livelihoods of millions of people, as it occurs on all continents (except Antarctica).Desertification takes place in drylands all over the world. Some 10 to 20%of all drylands may already be degraded, but the precise extent of desertification is difficult to estimate, because few comprehensive assessments have been made so far. A large majority of dryland populations live in developing countries. Compared to the rest of the world, these populations lag far behind in terms of human well-being, per capita income, and infant mortality. The situation is worst in the drylands of Asia and Africa. Dryland populations are often marginalized and unable to play a role in decision making processes that affect their well-being, making them even more vulnerable. Desertification has environmental impacts that go beyond the areas directly affected. For instance, loss of vegetation can increase the formation of large dust clouds that can cause health problems in more Desertification processes can lead to the formation of large dust clouds densely populated areas, thousands of kilometers away. Moreover, the that affects air quality and cause health problems thousands of kilometres social and political impacts of desertification also reach non-dryland away (Xinlinhot, China) areas. For example, human migrations from drylands to cities and other countries can harm political and economic stability.