Across vast areas of the world, human activity has degraded once fertile and productive land. Deforestation, overgrazing, continuous farming and poor irrigation practices have affected almost 2 billion hectares worldwide, threatening the health and livelihoods of over one billion people.

Such is the vagary of rainfall throughout Africa's rangelands that almost all pastoral communities face cycles of good and hardship years.

Southern Africa Development Communality (SADC) through its Regional Indicative Strategic Development Plan (RISDP) has set up an ambitious goal to double irrigation by 2015, which it sees as important component to sustain regional development and ensure food security.

The current debate on climate change, its impacts on socio-ecological systems and the role of agriculture has shifted from an emphasis on how to mitigate the effects of increasing greenhouse gas (GHG) emissions to how to prepare and adapt to the expected adverse impacts.