Desertification was defined at the Rio Earth Summit in 1992 as degradation of drylands,the point at which that land no longer can be returned to a productive state. It results from complex interactions between unpredictable climate variations but primarily human activities. The term desertification was first coined by French scientists and explorer Louis Lavauden in 1927.It involves the depletion of vegetation and soil.
Desertification is taking place much faster in the present world as compared to the past due to the increase of population that requires to grow crops and graze animals for survival.
What causes desertification? Is it due to climatic change?
One of the major cause of desertification is overgrazing due to the use of fences which has prevented the livestock from moving in response to availability of food.However,when used correctly,fencing is a good tool of veld management.But the core contention among all the environmental issues faced by planet Earth is Global Warming and consequent Climatic Change .The Inter-governmental Panel for Climatic Change (IPCC),formed out of the Kyoto convention decades before, has also released its report only a month before. The most significant conclusions of this report are:
Global Warming is not a scientific myth but a reality and holds great threat to development, progress and the survival of humanity.
A major cause of Global Warming is man made and is now known as “The Inconvenient Truth”.
Every country willing, Man has the know-how and technology to stall and reverse the process of Global Warming. But technological capability needs political support. (No discussion on the Geo-engineering practices proposed to combat Global Warming is attempted here).
Global Warming is produced by the increase of Green House Gases (Carbon dioxide, Nitrous oxides and Methane) in the atmosphere. Carbon dioxide, the main Green House Gas is produced by burning of fossil fuels in power plants and automotive sectors. Large forest fires too add up Carbon dioxide to the atmosphere. The increase of Carbon dioxide has been significantly high during last three hundred years, after the Industrial Revolution and has risen from 200 ppm (parts per million) to 280 ppm in the atmosphere. At the present rate of increase, the atmospheric carbon is slated to rise to 350 ppm by mid century and to more than 500 ppm by the century end. Such an increase of atmospheric Carbon dioxide is going to raise the global average temperature by 2.5 to 4 degree Centigrade. Rise of average global temperature melts polar ice and mountain glaciers, raises sea-level and endangers coastal submersion.A decrease or nil in the total amount of rainfall in drylands result in the destruction of topsoil and vital soil nutrients needed for food production also leading to desertification.Deforestation and incorrect irrigation practices in arid areas causing salinisation can prevent plant growth which in turn triggers desertification when coinciding with drought.
How widespread is desertification in the World and in India?
About one third of the world`s land surface is arid or semi-arid. It is predicted that global warming will increase the area of desert climates by 17% in the next century.
Worldwide desertification is making approximately 12 million hectares.This is equal to 10% of the total area of South Africa or 87% of the area of cultivated lands in our country.It is also devouring more than 20,000 square miles of land worldwide every year.Even the Sahara desert is advancing Southwards by about 5-10 kilometres per year.
Problems faced by the people due to desertification
In more than 100 countries,desertification is affecting 1 billion of the 6 billion world population forcing people to leave their farms for jobs in the cities.
It also reduces the ability of land to support life, affecting wild species, domestic animals, agricultural crops and people.
The reduction in plant cover that accompanies desertification leads to accelerated soil erosion by wind and water. South Africa is losing approximately 300-400 million tonnes of topsoil every year. Water is lost off the land instead of soaking into the soil to provide moisture for plants. Even plants that would normally survive droughts die. A reduction in plant cover also results in a reduction in the quantity of humus and plant nutrients in the soil, and plant production drops further.
As protective plant cover disappears, floods become more frequent and more severe. Desertification is self-reinforcing, i.e. once the process has started, conditions are set for continual deterioration.
Desertification can be stopped, but unfortunately is usually brought to public attention when the process is well underway.
Both individuals and governments can help to reclaim and protect their lands. Covering the dunes with large boulders or petroleum will interrupt the wind regime near the face of the dunes and prevent the sand from moving in areas of sand dunes. Shrubs and trees planted on the dune will also decrease the wind velocity and prevents much of the sand from moving.
More efficient use of existing water resources and control of salinization are other effective tools for improving arid lands. On a much larger scale, a "Green Wall," which will eventually stretch more than 5,700 kilometers in length, much longer than the famous Great Wall, is being planted in northeastern China to protect "sandy lands"--deserts believed to have been created by human activity. The World Day to Combat
Desertification is celebrated every year on June 17 all over the world to highlight the urgent need to curb the process of desertification and to strengthen the visibility of this drylands issue on the international environmental agenda.
The United Nations Convention to Combat Desertification (UNCCD) is the only internationally recognized, legally binding body that addresses the problem of land degradation in the drylands and which enjoys a truly universal membership of 191 countries.
It plays a key role in global efforts to eradicate poverty, achieve sustainable development and reach the Millennium Development Goals, in particular with regard to the eradication of extreme poverty.The need of the hour is to treat desertification as a wake-up call and to try and take it through strengthened community participation and cooperation at all levels.