Papers Selected from Contributions to the Sixth Meeting of the International Geographical Union's Commission on Land Degradation and Desertification, Perth, Western Australia, 20-28 September 1999

Desertification has occurred worldwide. The biophysical and socio-economic complexity of this phenomenon has challenged our ability to categorize, inventory, monitor and repair the condition of degraded lands. One of the most important distinctions to be made in relation to land degradation is between cultivated land used for annual crop production and `rangelands'. Grazing by free-roaming livestock is the traditional primary use of the world's rangelands. However, there is growing recognition of the importance of these vast acreages for wildlife habitat, hydrology and ground water recharge, recreation and aesthetics. This text focuses on the desertification of rangelands and explores processes, problems and solutions. Chapters in the first section evaluate interactions between `natural' and human-induced disturbance regimes, thresholds, and non-linear change with respect to vegetation, hydrology, nutrients and erosion. Chapters in the second section examine socio-economic constraints and approaches for preventing and reversing degradation. The book provides a contemporary, process-oriented perspective on rangeland degradation of value to students, policy-makers and professionals alike.

It now seems incontrovertible (as Alessandra Giannini has demonstrated) that the series of Sahelian droughts that began in the early 1970s were driven by changes in sea surface temperatures and that they were not caused by local land use mismanagement in the Sahel itself. Combined with the apparent re-greening of the Sahel, these findings effectively close a long-standing policy and scientific debate (in which the lead authors of this book participated) on the causes and extent of desertification in the Sahel. The opportunity now presents itself to treat this debate as a historical object lesson in the relationship between science, the formation of public opinion, and international policy-making in the context of climate change. In short, what might the ‘great Sahelian desertification boondoggle’ have to tell us about current attempts to come to grips with climate change?

After UNCED (United Conference on Environment and Development, Rio de Janeiro, July 1992), a second edition of Desertification was necessary. About 150 corrections, amendments and additions take scientific progress into account. The author also presents an updated chapter in which the results of UNCED are analyzed. This book aims at an understanding of what is commonly called "desertification" - a term which is proposed to be replaced by "land degradation". Each level of technology, excessive or insufficient, creates its own mismanagement. This is reflected in an increase in land degradation and eventually a decrease in soil productivity. The benefit to the reader is an awareness of the ecozones and a global overview of the phenomena, mechanisms and existing solutions.

This book (with a foreword by eminent desertification specialist, Dr. Alan Grainger of Leeds University) provides a synthesis of what desertification means in the present day context of worldwide concerns about land degradation in the face of global (including climate) change, burgeoning populations, urbanization, and loss of biodiversity. It defines and describes desertification in its many forms and examines efforts to combat land degradation. The authors present some models that relate to the current impact of climate change on desertification as well as the medium to long term, and offer case studies on efforts to combat desertification in the major regions of the world. In the last chapter, we attempt to synthesize the whole book in the context of the post-2015 agreements on climate change (the Paris Accord) and the UN Sustainable Development Goals (SDG). Chapters concerning the historical context of desertification consider the definition and meanings associated with the word desertification; discuss the global extent and severity of the many types of desertification; and explain the current status of desertification in the post-2015 context. The book also discusses the impacts of desertification on ecosystems and people along with biodiversity; dust and sand storms from desertified landscapes; and the people affected by desertification. Chapters also focus on desertification and climate change, and consider the nexus between climate, soil, water and people; climate variability, land use and livelihoods affected by desertification are also analyzed. Chapters on combating desertification focus on combating desertification and act as an overview of proven practices with a detailed case study from China. Finally, synthesis and conclusions are consider the future of those affected by desertification, dealing firstly with medium to long term future outlooks and secondly with attempting to sum up the trends.

Although much is known about the processes and effects of land degradation and climate change, little is understood about the links between them. Less still is known about how these processes are likely to interact in different social-ecological systems around the world, or how societies might be able to adapt to this twin challenge. This book identifies key vulnerabilities to the combined effects of climate change and land degradation around the world. It identifies triple-win adaptations that can tackle both climate change and land degradation, whilst supporting biodiversity and ecosystem services. The book discusses methods for monitoring effects of climate change and land degradation, and adaptations to these processes. It argues for better co-operation and knowledge exchange, so that the research, land user and policy communities can work together more effectively to tackle these challenges, harnessing the "wisdom of crowds" to assess vulnerability and adapt to climate change and land degradation, whilst protecting livelihoods and biodiversity.

Summarizes the science of climate change and impacts on the United States, for the public and policymakers.

This book is about the ‘how’ of desertification control as opposed to an analysis of the ‘why’ and fills a gap in the desertification-related literature in that it shows what to do in situations ranging from fixing mobile sands to arresting accelerated soil erosion in sloping lands. There are numerous illustrations to show the successful techniques. This compilation demonstrates that desertification and land degradation can be controlled and reversed with existing techniques in such widely varying environments as the Sahel of Africa to Sri Lanka and the Philippines in SE Asia, from mountains in Lesotho to low lands on desert margins in Mongolia. Proven approaches include technical interventions, changes in governance and to the legislative framework and policy reform. The book fills a gap in the desertification-related literature in that it shows what to do in situations ranging from fixing mobile sands to arresting accelerated soil erosion in sloping lands.

This book provides an examination into the causes and prospects of desertification through a systematic review of 132 sub national case studies. It uses a meta-analytical model to determine whether proximate causes and underlying driving forces fall into any patterns, to identify mediating factors, feedbacks, cross-scalar dynamics and typical pathways. It shows a limited set of recurrent core variables in varying combinations to drive desertification. Most prominent root causes are climatic factors, institutions, national policies, population growth and remote economic influences that lead to local cropland expansion, overgrazing and infrastructure extension, associated with desertification as a potential but not necessary outcome. Some factors are geographically robust; most of them are region and time specific.

Climate change poses many challenges that affect society and the natural world. With these challenges, however, come opportunities to respond. By taking steps to adapt to and mitigate climate change, the risks to society and the impacts of continued climate change can be lessened. The National Climate Assessment, coordinated by the U.S. Global Change Research Program, is a mandated report intended to inform response decisions. Required to be developed every four years, these reports provide the most comprehensive and up-to-date evaluation of climate change impacts available for the United States, making them a unique and important climate change document. The draft Fourth National Climate Assessment (NCA4) report reviewed here addresses a wide range of topics of high importance to the United States and society more broadly, extending from human health and community well-being, to the built environment, to businesses and economies, to ecosystems and natural resources. This report evaluates the draft NCA4 to determine if it meets the requirements of the federal mandate, whether it provides accurate information grounded in the scientific literature, and whether it effectively communicates climate science, impacts, and responses for general audiences including the public, decision makers, and other stakeholders.