Home What is desertification?

What is desertification?

Desertification does not refer to the expansion of existing deserts. It occurs because dryland ecosystems, which cover over one third of the world's land area, are extremely vulnerable to over-exploitation and inappropriate land use. Poverty, political instability, deforestation, overgrazing and bad irrigation practices can all undermine the productivity of the land.

Over 250 million people are directly affected by desertification, and about one billion people in over one hundred countries are at risk. These people include many of the world's poorest, most marginalized and politically weak citizens.

UNCCD Explanatory Leaflet


The definition of desertification has been a hotly debated question for a number of years. The word conjours up a landscape that is "turning into a desert" and implies irreversible loss of natural resources leading to decreasing productivity and impoverishment of the population. The problem is that the loss of natural resources has many causes, both natural and anthropic and the consequences are equally varied, from rural depopulation to soil salinisation. The many local variations in the appearance of desertification phenomena lead to many different uses of the word. In turn these different uses have meant that it has been difficult to reach agreement on how to combat it.


Desertification has been neatly defined in the text of the United Nations Convention to Combat Desertification (UNCCD) as


"land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities."


This is the definition that is now universally used (although still not everyone entirely agrees with it because it excludes other regions also vulnerable to land degradation).


And what is land degradation?
Again the UNCCD provides a useful answer. It is the loss of biological or economic productivity and complexity of croplands, pastures or forests resulting from land uses or processes including those arising from human activities. These processes include things like soil erosion, deterioration of the quality of the soil and long-term loss of natural vegetation.


Systematic presentation of the relation between desertification and land degradation (after »GIZ, 2011)


What parts of the world are affected by desertification?


All areas of the globe (apart from the polar regions) in which the ratio of annual precipitation to potential evapotranspiration falls within the range from 0.5 to 0.65 are potentially affected. But for the purposes of the UNCCD these include parts of Africa, Asia, Latin America and the Caribbean, the Northern Mediterranean and Central and Eastern Europe.

But the biggest problem is undoubtedly in Africa where a high proportion of the land and a substantial number of countries have low rainfall and high evapotranspiration rates. These are compounded by widespread poverty, difficult socio-economic conditions and heavy reliance of the populations on natural resources which lead to serious land degradation.


# Article Title
1 Easy-to-read booklets, leaflets and PowerPoints about different aspects of desertification in Europe


fp6 logo 3 50 x 43
The DESIRE project was 
co-funded by the
European Commission,
Global Change and
Contract no: 037046 GOCE

DESIRE brought together the expertise of
26 international research institutes
and non-governmental organisations.

This website does not necessarily
represent the opinion of the
European Commission. The European
Commission is not responsible for
any use that might be made of the
information contained herein.

Citing website content

For the terms under which the content 
of this website may be used see 
»Disclaimer, copyright and privacy

When referenceing page contents
please cite as Brandt, C. J. (ed). 
2012. "page title". DESIRE Project 
Harmonised Information System.
DESIRE Consortium.  

If citing a deliverable use the authors'
names, date and title as given on the 
cover page and add "available at 

Follow us