At the end of November, 159 nations met in Recife, Brazil to move ahead on one of the great problems besetting the planet: desertification.
Deserts are spreading over a 2-million-square-mile region of dry-lands inhabited by 2 billion people - one-third of the earth's population. Every year, some 23,000 square miles of arable and range land are irretrievably lost, with consequences for the entire globe.
The Recife Conference was little noticed, if at all, in the United States. The nations at the meeting are parties to the UN Convention to Combat Desertification (CCD), which, along with treaties on climate change and biodiversity, emerged from the Earth Summit in Rio de Janeiro in 1992. The US is not a signatory but sent an active delegation to Recife; since the dust bowl of the 1930s, the US has dealt with its desertification problem on its own.
The areas at risk are mainly in Africa, but also in Asia and the Americas. Such vast deserts as the Sahara, Gobi, and Arabia aren't at issue, only those regions where people struggle to wrest a living from the land.
Desertification is not necessarily encroachment by sand dunes, but gradual loss of soil fertility through excessive cultivation or grazing, destruction of shrubs and trees for firewood, and mismanagement of available water. The upshot, as population and poverty increase, is a vicious cycle: greater pressure on less land, and more desert.
The impact of this process is severe. The poorest farmers give up and migrate to cities in search of a livelihood. One estimate suggests more than 100 million people may be forced to move in coming years.
Necessity is already sending them across international boundaries, and Europe is especially worried. Poverty is the enemy of health and education. The UN Environmental Program calculates that desertification reduces the world product by $40 billion a year.
Scientists point to other effects far beyond the obvious. Dry-land soil contains much organic matter that stores carbon dioxide, the most common of the "greenhouse" gases that cause global warning.