This volume has traced the development of the Mediterranean landscape over very long timescales and has examined modern processes in a wide range of settings. Earlier chapters have explored tectonic processes and the evolution of the topography and biota, the nature and impact of Quaternary climate change, and natural hazards, as well as the increasing role of human activity in shaping geomorphological processes and ecosystems during the course of the postglacial period. A core theme in several chapters is the nature of the relationship between humans and the Mediterranean environment. Over the last one hundred years or so, and especially in the period since the Second World War, this relationship has changed dramatically. Resource exploitation, urban expansion, and rural depopulation have all taken place at unprecedented rates, with major impacts upon the quality of land, water, air, and ecosystems. The final part of this volume examines four key topics of environmental concern; its four chapters explore, respectively, land degradation, water resources, interactions between air quality and the climate system, and biodiversity and conservation. Where possible, it is important to place these issues within an appropriate historical perspective. Many components of the Mediterranean environment have responded in a sensitive way to past environmental changes, but the pressures on land and water resources have never been more intense. Improved monitoring networks and new modelling efforts are needed to predict more effectively the impact of climate and social change on all environmental systems and to help inform policymakers seeking a more sustainable use of the region’s resources. Chapter 20 examines the ecological aspects of land degradation and sets out new ideas on productivity dynamics. It explores some of the interactions between land use change, vegetation dynamics, grazing patterns and wildfires. The uneven geography of water resources and water use are highlighted in Chapter 21. Water resource issues have become an increasingly important factor in the geopolitics of the region against a background of climate change uncertainty, rising demand, and a diminishing resource base. Chapter 22 analyses the interactions between climate, air quality, and the water cycle.
CLIMATE CHANGE, LAND DEGRADATION, AND DESERTIFICATION IN THE MEDITERRANEAN ENVIRONMENT