“Continued land degradation – whether from
climate change, unsustainable agriculture or poor management of water
resources – is a threat to food security, leading to starvation among
the most acutely affected communities and robbing the world of
productive land,” Secretary-General Ban Ki-moon said in a message to the
… launch of the Decade for Deserts and the Fight against Desertification in Fortaleza, Brazil, where the UN Convention to Combat Desertification (UNCCD) should get some implementation boost.

Desertification is defined as the degradation of drylands, which comprise more than 40 per cent of the worlds land surface and are home to 2.1 billion people one in every three people worldwide.

Source: http://www.un.org/apps/news/story.asp?NewsID=35633&Cr=desert&Cr1