Twenty years have passed since the last atlas of desertification was published.
Within that short period enormous global changes have taken place
in terms of human expansion and the impact that had on the environment.
Equally significant progress has been made in understanding the fundamentals
of human-environment interactions.This has been made possible, in part,
by the massive increase >and growth in the accessibility of global and

WAD3 thus begins at a very different place than WAD2 in terms of scientific
information and understanding.
That said, we are also confronted by the rapidly growing appreciation
of the complexity of the land degradation phenomenon and
all the human factors that both drive it and are derived from it.
As a consequence, rather than attempting to produce a comprehensive
global model that cannot deliver useful local or regional information,
WAD3 offers an approach that accommodates and embraces these
complexities and is intended to provide an information framework
from which to pursue solutions that fit specific local situations.

Although ‘desertification’ remains in the title, this atlas represents a significant departure from the first two editions of the World Atlas of Desertification because deterministic maps on global land degradation are not presented. Rather, land degradation is considered to be a global problem of human dominance involving complex interactions between social, economic and environmental systems, which is not amenable to mapping.

Historical Perspective


In 1977, the United Nations Conference on Desertification (UNCOD) adopted an action plan to Combat Desertification informed by a map of desertification made by FAO, UNEP and UNESCO. In 1991, UNEP concluded that the problem of land degradation in arid, semi-arid and dry sub-humid areas had intensified. This was based on the GLASOD map compiled in 1990, which was used in WAD1 in preparation for the UN Conference on Environment and Development (UNCED) held in Rio de Janeiro in 1992.
Based on the recommendation of UNCED, the United Nations General Assembly, established the UN Convention to Combat Desertification (UNCCD). The Convention was adopted in 1994 and entered into force in 1996. As decided in 2007, the Committee for Science and Technology convened three scientific conferences in 2010, 2013 and 2015. At the 2007 UNCCD COP8, a ten-year strategic plan was adopted, inviting stakeholders to compile a new atlas and, in response, the JRC accepted the task of coordinating the compilation of WAD3.

Current Perspective

This third edition of the World Atlas of Desertification focuses on land degradation and global environmental change under five major subject headings:
Global Patterns of Human Domination. Highlighting the role of Homo sapiens as the major driving force of global environmental change;
Feeding a Growing Global Population. The ability to feed 10-12 billion humans by the end of the century is one of the great challenges facing humanity, creating enormous burdens on the land;
Limits to Sustainability. The Brundtland Commission defined sustainable development as “development which meets the needs of the present, without compromising the ability of future generations to meet their own needs”. There are numerous obstacles that must be overcome to achieve this goal;
Converge of Evidence. Many of the anthropogenic-induced environmental changes can be measured and their combined effect are indicative of the multiple stresses humans exert on the land. WAD3 draws on this complexity by adopting the concept that evidence or signals from multiple sources may “converge”, thus leading to the development of testable hypotheses and/or conclusions that are supported by data. Convergence of evidence maps replace ‘maps of desertification’ as per WAD1-WAD2;
and Solutions. Potential solutions to land degradation need to be identified and implemented within the context of local social, economic, and political conditions.

Key messages:

  1. Underlying and familiar factors -- some old, some new -- are driving environmental change/land degradation at a global scale;
  2. Some recurring global issues (such as surface and ground water) have an alarming urgency that could not be known 20 years ago;
  3. There is a growing confirmation of suspected global trends (such as a decline in productivity) that may impact sustainability;
  4. Global issues that were only suspected previously will shape how we look at both processes and solutions (such as telecouplings; smallholders vs. largeholders);
  5. Some regional patterns of potential degradation are reconfirmed (south Asia; China) and some underlying causes are revealed (heavy fertiliser use and irrigation);
  6. New regional patterns of potential land degradation are revealed (especially in central Asia);
  7. Concerns emerge at the regional level that brings into question our ability to meet the demands of future populations, e.g. maintaining and increasing yields on highdensity croplands and increasing crop yields (by closing yield gaps) on low-density and low-input croplands;

Underlying global trends

By 2050 the world’s population will exceed 9 billion. To meet the increased demand for food, fibre and energy, pressure on the planet’s finite natural resources will be exacerbated. Significant trends include:

Urbanisation. The proportion of the population residing in urban areas will continue to rise, particularly in drylands. Urban areas and their supporting infrastructure will continue to consume agriculturally productive lands.
Climate change. Over the remainder of this century, the climate of the globe is expected to become both warmer and drier. In concert with the growth of urban areas, much of the pressure of climate change will be felt in urban areas, particularly in the drylands.
Dietary changes. Over the past 50 years, increases in population income has brought about a shift in human diet preferences away from foods largely derived directly from plants, to one increasingly focused on animal products (milk, meat, eggs). This trend significantly exacerbates the pressure on finite resources of the land.

Global issues: Recurring
Old issue, new urgency. New global data on the Earth’s water resources highlight this critical issue. While surface water area is greater than any time in the past 30 years, much of this is due to the construction of dams. Dams may benefit local interests but threaten livelihoods and environments downstream, often across international borders. The dynamics of global groundwater, which were unknowable 20 years ago, show alarming declines; this is especially the case in areas of highdemand (e.g. irrigated agriculture). Global patterns of surface and ground water indicate the need to manage risk and strategically plan for water shortages, especially since the human population is growing, demand for water is increasing, and the threat of climate change adds increasing uncertainty.

Global trends: Potential
Declining land productivity. There is a concern that the productivity of the land resources of the Earth is declining.

Global issues: New
Telecoupling. The globalisation of the world’s economy has environmental consequences, which were little considered 20 years ago. Now, changes in land use may be geographically displaced. For example, increased demand for agricultural products in developed countries (e.g. Japan) may cause deforestation in developing countries (e.g. Brazil) to meet that demand. Moreover, the export of products (e.g. maize) from one country to another involves not only the grain itself, but the water required to produce it. As our understanding of environmental lifecycle accounting and international value chains grow, so too must our appreciation of the true costs versus benefits.
Smallholders and largeholders. The role of smallholders as agents of land management and environmental change has been underappreciated (Section 7). More than 80 % of all farms on the planet are less than 2 ha in size and are managed by poor households. The types of technology that must be adopted globally to increase agricultural production, while minimising or reversing environmental impacts, is dependent on how well potential interventions match existing management strategies and the ability of smallholders to adapt.

Regional patterns: Old and New
Although WAD3 does not offer a comprehensive assessment of global land degradation, there were a number of findings that emerge when examining multiple global data sets with an analytic framework (i.e. convergence of evidence):
Familiar patterns, old concerns
A number of key issues ‘converge’ throughout the Sahel and eastern Africa. This includes yield gaps, decreased productivity and chronic low-income.
Transformation of forest to irrigated farmlands threatens vast areas of the Chaco in Argentina, Paraguay, and Bolivia.
In densely-populated areas of Europe and N. America, urban expansion is consuming land resources and high-intensive agriculture requires large, continuous inputs of nutrients.
Familiar patterns, new concerns.
The coincidence of many issues in the northern part of south Asia, largely within the Indo-Gangetic plains of India and Pakistan and the North China plain, suggest the potential for land degradation. Most notable are the high population densities, dependence on high inputs of fertilisers, and the persistence of low income levels. Some new issues have emerged in WAD3 that underscore these concerns. In particular, the dominance of smallholders in both south Asia and China suggest challenges and vulnerabilities that may have been underappreciated in the past. Moreover, alarming declines in groundwater in both areas may foreshadow significant problems in the future, particularly in the face of climate change.
New patterns, potential concerns.
The vast wheat-producing region developed by the former Soviet Union emerged as an area of concern. Large-scale, lowput agricultural operations, mainly in sparsely population parts of Russia and Kazakhstan, are seen as a potential opportunity to increase global agricultural production but also as a potential environmental threat. Production increases could be achieved by increasing fertiliser inputs. Projected changes in climate may also make these areas more favourable for agricultural intensification. However, much of the land currently in production is marginally productive, and may have higher value as habitat. Moreover, increases in fertiliser inputs could have negative impacts on water resources and adjacent habitat.