http://www.anba.com.br/ingles/especial.php?id=285

Advance of desertification is a global concern

......The degree of urgency in discussing this matter has caused the United Nations (UN) to proclaim the year of 2006 the International Year of Deserts and Desertification. The objective is to present desertification as the main threat to humanity, strengthened by sceneries of climate change and loss of biodiversity.

Desertification is one of the most alarming processes of environmental degradation in the world. Each year, desertification and drought cause losses of US$ 42 billion in agriculture. The risks of desertification are substantial and clear. They contribute to food insecurity, hunger and poverty, and may increase social, economical and political tensions that, in turn, cause conflict, greater poverty and degradation of the earth.......

How many advanced societies in history, have fallen by the wayside, as the water goes.