Is Earth, our planet, losing its name? The earth is being degraded. According to estimates, 24 billion tons of fertile soil disappear annually and over the past 20 years, the surface area lost is equal to all of the farmland of the United States of America. Roughly one third of the world’s land surface is threatened by desertification, or put in another way; desertification already affects one quarter of the total land surface of the globe today.
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’ (UNCCD Art.1.a). Desertification is a dynamic process that is observed in dry and fragile ecosystems. It affects terrestrial areas (topsoil, earth, groundwater reserves, surface run-off), animal and plant populations, as well as human settlements and their amenities (for instance, terraces and dams).
4: Desertification is caused by the complex interactions between
physical, biological, social, cultural and economic factors.
Spontaneous or human induced bush
and forest fires can severely degrade the environment.
The United Nations Convention to Combat Desertification adopted a definition of desertification that attributes the causes of this phenomenon to both climatic variations and human activities. It adds, ‘desertification is caused by complex interactions among physical, biological, political, social, cultural and economic factors’.
Climatic variations: High and sustained temperatures lasting for months with infrequent and irregular rainfall, leads to drought with the effect that vegetation has difficulty growing. This natural phenomenon occurs when rainfall is less than the average recorded levels. As a result, severe hydrological imbalances jeopardize production systems.
Human activities: in countries where major economic resources are dependent on agricultural activities, there are few or no alternative sources of income. Soils become damaged through excessive use when farmers neglect or reduce fallow periods, necessary to sufficiently produce enough food to feed the population. This in turn causes soil to lose organic matter, limiting plant growth and reducing vegetation cover as a consequence. The bare soils are thus more vulnerable to the effects of erosion.
When violent winds and heavy downpours destroy the vegetation, which is then carried away by the sudden gushes of water, the harvests tend to be poorer and the livestock suffer, they eventually become malnourished. As a consequence, the income of the rural communities diminishes. According to the Convention, land degradation brings about a decline or an end to soil productivity, vegetation, arable and grazing lands, as well as forests. In the most extreme cases, hunger and poverty set in and become both the cause and consequence of land
Combating desertification requires a coherent and co-ordinated policy that brings together the means and know-how of all those involved. It is within this framework that governments around the world have developed the United Nations Convention to Combat Desertification (See Unit 14).
5. California in the USA:
Coachella Valley, Mecca Hills. Desertification is a global phenomenon that affects
every continent regardless of its level of economic development. In developed regions,
such as California, eroded areas and land degradation are also found.
© Yann Arthus-Bertrand
The Convention is an agreement between developed and developing countries on the need for a global team effort to address desertification. It includes specific national commitments for concrete action at the local level where the combat against desertification must primarily and vigourously be fought.
Actions to undertake to combat desertification Combating desertification comprises activities that improve lands in arid, semi-arid and sub-humid areas with a view to sustainable development (See Unit 17).
The moment has arrived to begin your wall chart!
All the pupils are invited to participate in classroom activities: drawing, writing, collages etc.
They will be proposed throughout the desertification course and can be added to the desertification wall chart. Begin by tracing the contours of the world’s continents on a large piece of blank paper (See world map on the desertification poster).
Each pupil writes on a separate piece of paper a word that symbolizes the desert. The pieces of paper are then folded and collected.
A pupil then selects one of them by chance and draws on the blackboard, in the form
of a pictogram, the word corresponding to the desert. The class must guess the word.
Each pupil can begin his/her desertification notebook by writing down activities on combating desertification.
The pupils can also draw, paint and paste photos about their environment and on the desert in their notebook.
Ask the pupils to define desertification at the beginning of their