Combating desertification

Kew’s work on the Great Green Wall initiative is highlighted by Moctar Sacande, to mark the United Nations’ World Day to Combat Desertification.

Royal Botanic Gardens Kew – BY MOCTAR SACANDE

Desertification, along with climate change and the loss of biodiversity were identified as the greatest challenges to sustainable development during the 1992 Rio Earth Summit. In 1994, the United Nations responded by establishing the Convention to Combat Desertification (UNCCD) as the sole legally binding international agreement linking environment and development to sustainable land management. The Convention specifically addresses the drylands, where some of the most vulnerable ecosystems and peoples can be found. The Convention between 195 parties/ countries specifies that its goals are to work together and forge a global partnership in order to reverse and prevent desertification/ land degradation in order to support poverty reduction and environmental sustainability. 

The Convention works to improve the living conditions for people in drylands, to maintain and restore land and soil productivity, and to mitigate the effects of drought in affected areas. It is particularly committed to a bottom-up approach, encouraging the participation of local people in combating desertification and land degradation. It facilitates cooperation between developed and developing countries, particularly around knowledge and technology transfer for sustainable land management. As the dynamics of land, climate and biodiversity are intimately connected, the Convention collaborates closely with different institutions to meet these complex challenges with an integrated approach and the best possible use of natural resources.


Desertification is defined in the first Article of the Convention as land degradation in drylands resulting from various factors, including climatic variations and human activities; with ‘land degradation’ being a reduction or loss of the productivity and complexity of rainfed crop-land, irrigated crop-land, or range, pasture, forest and woodlands (UNCCD 1994). These depletions result from land (mis)uses or from a combination of processes, including processes arising from human activities and habitation patterns, such as:

  • soil erosion caused by wind and/ or water
  • deterioration of the physical, chemical and biological or economic properties of soil
  • long-term loss of natural vegetation

Across the world, around 25% of usable land is highly degraded, leading to biodiversity loss, food insecurity, scarcity of clean water and pest increase. This results in the affected areas’ populations becoming more vulnerable to climate change. As the global population continues to grow, so too does the risk that usable land may not be able to meet its demands. It is therefore essential to work together and reverse land degradation wherever possible, restoring degraded ecosystems and managing land resources sustainably.

Land degradation is becoming an increasingly high-profile issue at the international level. Desertification has its most significant effects in Africa, where two-thirds of the continent is desert or drylands. However, one of Africa’s solutions is the implementation of the Great Green Wall (GGW) initiative for the Sahara and the Sahel (AUC 2012). Globally, the Bonn Challenge (2011) and the New York declaration on Forests (2014), together aiming to restore 350 million hectares of degraded land by 2020, are practical actions that support land degradation neutrality.

Kew’s contribution to combating desertification

Kew’s Millennium Seed Bank (MSB) has banked seed collections of about 36,000 species since the start of its international programme in 2000, giving a priority to the drylands of Africa, Australia and Latin America where there is pressing need to conserve biodiversity and vulnerable species. This makes it one of the largest ex situ collections of wild species in the world. From 2007 onward, by focussing on enabling the use of these collections, the MSB has supported seed and seedling planting and livelihoods restoration of agrosylvopastoral systems, involving rural communities in Africa in particular (see UPP & GGW projects).

Author: Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.