Land Use and Global Environmental Change

Abstract

Changes in land use and land cover have contributed substantially to the increased CO₂ content of the atmosphere, have exacerbated shortages of water, have substantially changed biogeochemical cycles on earth, and are causing dramatic losses of biodiversity around the globe. The combined effects of these forces on global climate, biodiversity, water availability and ecosysteminxxecosystem vulnerability amongst others are generally denoted as global environmental change. Land use links human activities to land cover. Changes in land use and land cover are largely related to changes in the exploitation of land. The demand for agricultural land has increased, mainly triggered by the growing and changing food demand from an ever-increasing population. In areas where land is scarce the need to maintain food production with growing demand is achieved via technological changes in land use accomplishing higher returns per the area of land. Where land was abundant, land conversion remained the main strategy. The growing demand on scarce land resources has resulted in additional environmental stress. On the other hand, the intensification of land use, which was successful in increasing food production, has been damaging to the environment. Today’s environmental challenges arise both from the lack of development and from the unintended consequences of some forms of economic growth (Brundtland et al., 1987). Figure 1.1 (Vitousek et al., 1997) shows examples of the impact of man’s activities in the form of estimates of the percentage transformation of the earth’s surface. Land-use and land-cover changes are thus prime and central phenomena in shaping today’s world and its climate.