SciDev.Net

This document is a three-tier summary of the 'Ecosystems and human well-being: desertification synthesis' report published by the Millennium Ecosystem Assessment (MA) in 2005. It begins with nine questions and answers introducing the subject, defining desertification, its causes, effects and how it can be better understood.

Answers are then further developed, addressing sub-questions such as how vulnerable are affected populations? And what social, economic and policy factors contribute to desertification?

Finally, it uses extracts from the MA report itself to support the arguments made.

The document estimates that 10-20 per cent of drylands are degraded and identifies desertification as a major environmental challenge affecting some of the world's poorest populations. The MA report suggests prevention as the most effective way to cope with desertification but argues that reducing the pressure on dryland resources must be accompanied by efforts to reduce poverty, as the two are closely linked.

Aimed at an expert audience, this report is an authoritative and up-to-date assessment of the state of the world's deserts, written and edited by some of the leading names in desert science. The report defines deserts to include all arid and hyper-arid parts of the Earth — some 25 per cent of land surface.

In addition to assessing the future of deserts, the report also highlights the links between deserts and climate change. It shows, for example, that between 1976 and 2000, global climate change contributed to rising temperatures in nine out of the 12 deserts studied. With temperatures set to rise further still, the Sahara is predicted to become drier, according to the report. The Gobi desert, on the other hand, is likely to receive more rain.

The report calls for more enlightened policies to improve the quality of life in deserts. In particular, it advocates moving away from plans that are energy and water-intensive, and instead supporting those that combine traditional wisdom on coping with drought with modern science and technology for sustainable resource management.

Where are the world's drylands? Who lives in them? How can the condition of soils be measured? This short book from the World Resources Institute (available in print and as an online download) answers these and many more fundamental questions on drylands and their relationship with people and ecology. Accessible and authoritative, it tells the reader that world's largest area of dryland is in Australia, followed by the United States, Russia, China, India and Kazakhstan. Most dryland people live in Asia (1.4 billion), followed by Africa (270 million) and the Americas (150 million).

The UN Environment Programme, based in Nairobi, periodically assesses the world's environment in Global Environment Outlook (GEO). This report can be downloaded as a PDF file as well as a set of free online data tables. GEO includes a neat summary of the extent, causes and severity of land degradation in different regions, as well as the relationship between biodiversity, climate change and land. GEO also includes data tables on how much land is under cultivation; the area of land being irrigated; and trends in fertiliser consumption. GEO is among the premier resources for factual information on dry lands, although its website's navigation could be improved. More for specialist readers.

For a rapid summary of current knowledge on deserts and drylands aimed at the general reader, the American Association for the Advancement of Science's (AAAS) four-page guide is hard to beat — even though it is a little out of date. The guide includes data on soil degradation around the world; a list of countries with large dryland areas; and a world map of dry lands. It acknowledges the uncertainty over the definition of desertification. It also points out that satellite images show the desert advancing and retreating several times since 1980 in regions such as the Sahel, depending in part on when it rains. The guide is published in the AAAS Atlas of Population and the Environment, which can be ordered or downloaded from this website.

Compiled from the archive of India's fornightly Down to Earth magazine, Global Environmental Negotiations is an impressive two-volume book that provides comprehensive information on the history and prospects of all UN multilateral environmental agreements, including the conventions on biodiversity, climate change and desertification.

The volumes are particularly valuable in that Down to Earth is perhaps the only southern-based periodical that has been closely following global environmental issues for well over a decade; they are intended as aids to negotiators and civil society across the world.