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Facts and Figures: Desertification and Drought
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The World Day to Combat Desertification and Drought, celebrated every year the 17th of June, marks the anniversary of the adoption of the United Nations Convention to Combat Desertification (UNCCD), in 1992, based on a recommendation of the Rio Earth Summit.
What is desertification?The UNCCD defines desertification as the degradation of land in arid, semi-arid and dry sub-humid areas. Desertification occurs in arid, semi-arid and sub-humid areas - where the soils are especially fragile, vegetation is sparse and the climate particularly unforgiving. These areas are inhabited by one fifth of the world’s population.
1/3 of the earth’s land surface (4 billion hectares) is threatened by desertification, and over 250 million people are directly affected by desertification. 24 billion tons of fertile soil disappear annually. From 1991 to 2000 alone, droughts have been responsible for over 280,000 deaths; they accounted for 11% of the total water-related disasters.
What are the causes of desertification?Desertification comes mainly from variations in climate and from human activities, but many other causes can interact to create conditions likely to lead to desertification. These include the movement of refugees during periods of conflict, inappropriate land use or environmental management, specific socio-economic and political factors.
Climatic variations
High temperatures lasting for months create droughts that prevent the vegetation from growing.
Human activities
Human activities leading to desertification are mainly related to agriculture:
 | The result of overgrazing on the outskirts
of Amman city, Jordan.
© FAO, R. Faidutti |
 overgrazing removes the vegetation cover that protects it from erosion
overcultivation exhausts the soil
deforestation destroys the trees that bind the land to the soil. Wood is the principal source of domestic energy for lighting and cooking in many arid areas.
poor irrigation practices raise salinity, and sometimes dry the rivers that feed large lakes: the Aral Sea and Lake Chad have shrunk dramatically in this way.
The intensification of human activities brings an increased greenhouse effect, causing global warming. Drylands are likely to be especially vulnerable to rises of temperature during the 21st Century.
Poverty and desertification: the vicious circleEconomic pressures can lead to the over-exploitation of land, and usually hit the poorest hardest. Forced to extract as much as they can from the land for food, energy, housing and source of income, they are both the causes and the victims of the desertification. International trade patterns are based on the short-term exploitation of local resources for export, acting against the long-term interests of the local people. Poverty leads to desertification, which in turn leads to poverty.
The impacts of desertificationDesertification affects all aspects of life, highlighting how much environment and livelihoods are interlinked.
 | Dead vegetation in drought-stricken area,
Sol-Dior area, Senegal.
© FAO, Ch. Errath |
Environmental impacts
Because of the vegetation loss, desertification makes areas more flood-prone. It also causes the salt level in soil to rise, results in deteriorating quality of water, and silting of rivers, streams and reservoirs.
Economic impacts
Desertification has huge economic consequences – the World Bank estimates that at the global level, the annual income foregone in the areas affected by desertification amounts to US$ 42 billion each year, while the annual cost of fighting land degradation would cost only US$ 2.4 billion a year.
Poverty and mass migration
Land degradation brings hunger and poverty. People living in areas threatened by desertification are forced to move elsewhere to find other means of livelihood. Usually they migrate towards urban areas or go abroad. Mass migration is a major consequence of desertification.
From 1997 to 2020, some 60 million people are expected to move from the desertified areas in Sub-Saharan Africa towards Northern Africa and Europe.
What are the regions most threatened?In all, more than 110 countries have drylands that are potentially threatened by desertification. Africa, Asia and Latin America are the most threatened by desertification.
Africa
2/3 of the continent is desert or drylands in Africa. There are extensive agricultural drylands, almost three quarters of which are already degraded to some degree. The region is afflicted by frequent and severe droughts. Many African countries depend heavily on natural resources for subsistence. Africa's desertification is strongly linked to poverty, migration, and food security.
Asia
Asia contains some 1.7 billion hectares of arid, semi-arid, and dry sub-humid land reaching from the Mediterranean coast to the shores of the Pacific.
 | Result of severe and accelerated erosion
caused by the strong North and North-east
winds in the Horquin Desert, Inner Mongolia,
China. © FAO, J.Y.Piel |
Degraded areas include expanding deserts in China, India, Iran, Mongolia and Pakistan, the sand dunes of Syria, the steeply eroded mountain slopes of Nepal, and the deforested and overgrazed highlands of the Lao People's Democratic Republic. In terms of the number of people affected by desertification and drought, is the most severely affected continent.
Latin America and the Caribbean
Although better known for their rain forests, Latin America and the Caribbean are actually about one-quarter desert and drylands. Poverty and pressure on land resources are causing land degradation in many of these dry areas.
Other regions and countries affected by desertification
Much of the Northern Mediterranean region is semi-arid and subject to seasonal droughts. It is also marked by high population densities, heavy concentrations of industry, and intensive agriculture. Mediterranean land degradation is often linked to poor agricultural practices.
The level of soil degradation is high through much of Central and Eastern Europe, and very high in some parts, for example along the Adriatic.
30% of the land in the United States is affected by desertification.
How can we act against desertification?Restore and fertilize the land
A simple and cheap way to fertilize the land is to prepare compost, that will become humus and will regenerate the soil with organic matter.
 | Building barriers (fences) to prevent advance
of sand dunes at Gour, Niger. Fences are
mainly built with the local bush or with dead
palm leaves. © FAO, P.Cenini |
Combat the effects of the wind
By constructing barriers and stabilising sand dunes with local plant species.
Reforestation
Trees play several roles: they help fix the soil, act as wind breakers, enhance soil fertility, and help absorb water during heavy rainfall.
Because the burning of land and forests increases dangerous greenhouse gases, afforestation – planting new trees - can help reduce the negative impacts of resulting climate change.
 | Erosion control by planting grass in rows
on steep slopes in India.
© FAO, G. Blaak |
Develop sustainable agricultural practices
Drylands are home to a large variety of species, that can also becomeimportant commercial products: for example, they provide 1/3 of the plant-derived drugs in the United States. Agriculture biodiversity must be preserved. Land overexploitation shall be stopped by leaving the soil ‘breathe’ during a certain-time period, with no cultivation, nor livestock grazing.
Traditional lifestyles
Traditional lifestyles as practiced in many arid zones offer examples of harmonious living with the environment. In the past, nomadism was particularly adapted to drylands conditions; moving from one waterhole to another, never staying on the same land, pastoral peoples didn’t exert much pressure on the environment. However, changing lifestyles and population growth are putting increasing pressure on scarce resources and vulnerable environments. The Silk Road in Asia and the Trans-Saharan route in Africa are good examples of the vigourous economic and cultural exchanges developed by nomadic societies.
Milestones: The response of the international community to desertification1977 – United Nations Desertification Conference, Nairobi
A response of the international community to the most severe droughts in sub-Saharan Africa during the last 1960’s and early 1970’s: over 200,000 people and millions of animals died. A first Plan of Action to Combat Desertification emerged.
1992 – United Nations Conference on Environment and Development, Rio de Janeiro
Agenda 21 called on the UN General Assembly to set up an inter-governmental committee to prepare for a legally binding instrument that addresses the problem of desertification.
1994 – Adoption of the United Nations Convention to Combat Desertification (UNCCD)
June 17 becomes the World Day to Combat Desertification.
2002 – World Summit on Sustainable Development, Johannesburg
Governments call on the Global Environment Facility (GEF) to designate land degradation as a focal area of the GEF as a means to enhance the provision and mobilization of financial resources for the effective implementation of the UNCCD.
For more information visit the Water Library.
Information based on:
United Nations Convention to Combat Desertification (UNCCD) website
Media Brief for the World Day against Desertification and Drought
Learning to combat desertification (UNESCO/MAB)
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 Learning to combat desertification
MAB website
This educational kit on desertification is principally targeted to teachers of primary school education and their pupils, aged 10-12 years old. Its positive approach demonstrates that desertification is not inevitable and that everyone, at his or her own level, has a role to play in Earth's future. It includes a teacher's guide, a set of case studies, two cartoons and a wall poster.
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 Desertification
The United Nations Convention to Combat Desertification defines the term desertification as 'land degradation in arid, semi-arid and sub-humid areas resulting from various factors including climatic variations and human activities'. |
Erosion
A phenomenon resulting from the action of the wind (wind erosion) or from water (hydraulic erosion) that brings about the removal of top soil and the degradation of rocks. |
Rainforest
Luxuriant forest, generally composed of tall, broad-leaved trees and usually found in wet tropical uplands and lowlands around the Equator. |
Salinisation
A net increase of the salt content of the soil leading to a productivity decline. Salinity problems are due either to intrusion of seawater or to inland salinisation, mainly caused by improper irrigation methods. |
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