During the past half-century, shrinkage in the availability of natural resources occurred more rapidly than in any comparable time in history, driven in great part by human intervention in the environment in the form of agricultural activities. Although vital to the production and supply of food, feed and fuel, these have had negative environmental and socio-economic consequences, such as land degradation, water pollution, climate change, biodiversity loss, reduced long-term productive capacity, poverty, migration and ill health (International Assessment of Agricultural Knowledge, Science and Technology for Development, 2009). Defined as a long-term decline in ecosystem function and productivity, land degradation is driven mainly by poor land and water management, including over-cultivation, overgrazing, deforestation and inadequate irrigation (Berry, Olson and Campbell, 2003). While agriculture contributes significantly to the problem of climate change, it is also vulnerable to its effects.