Land Degradation Worse Than Previously Reported

Land degradation is becoming worse in severity and extent across many regions of the world, with croplands, in particular, declining in function and productivity, the U.N. Food and Agriculture Organization said in a new report.

Prior to the release of the report last Wednesday, U.N. Environment Program-funded research had estimated that between 10 and 20 percent of the world's 1.5 billion hectares of cropland suffered from some level of degradation. Now, using satellite imagery for the years between 1981 and 2003, the FAO researchers estimate that 24 percent of all land surface area is depleted.

Despite the world undergoing a crisis of food supply shortages, funding and research dedicated to global land degradation is sparse. In this report, the FAO called for individuals, communities, and governments to dedicate "renewed attention" to the state of the world's soil, citing food security and climate change mitigation as reasons for concern.

Consequences of land degradation include reduced productivity, farmer migration, food insecurity, ecosystem failure, and biodiversity decline.

Cropland occupies only 12 percent of global land area, but it accounted for 20 percent of the land considered degraded. When this occurs, the poor often struggle to raise enough money for the fertilizers that could avoid reduced yields.

Farming methods are generally the cause for degradation. Excessive tillage and removal of vegetation often encourage soil erosion by exposing the soil to rain and wind. Overgrazing by cattle and the build-up of salt on irrigated land are major contributors, as well.

Degradation has historically been considered a problem of tropical, developing nations. Sub-Saharan Africa is still most severely affected. The region contains 13 percent of global degraded area, while nations such as Swaziland are almost entirely located on degraded soil.

The degradation that has occurred over the past 23 years, however, mostly affects new areas. According to the report, nations such as China, Argentina, and South Africa are now facing greater problems than before.

More assessment of land degradation has become crucial, the authors noted. "Quantitative, up-to-date information is needed to support policy development for food and water security, environmental integrity, and economic development," the report said.

The study follows the International Assessment of Agricultural Science and Technology for Development's April report that called for a worldwide "paradigm shift" towards more sustainable agriculture. Among the suggestions, it called for government support of small-scale irrigation and greenwater technologies for degraded croplands, such as in Sub-Saharan Africa.

A 1994 UN Convention to Combat Desertification, signed by 191 nations, agreed to promote sustainable development in affected areas. But funding has so far been lacking. Following a conference last year, 70 non-governmental organizations said "constant passiveness" and "absences of intervention" by signatory nations have stalled progress on land degradation.

Ben Block is a staff writer with the Worldwatch Institute. He can be reached at bblock@worldwatch.org.