Climate Impacts of Land Degradation in the World’s Drylands

Drylands throughout the world have always undergone periods of degradation due to naturally-occurring fluctuations in climate. However, over the past century, the human population in drylands has grown exponentially and the resulting pressures on the landscape have exacerbated various desertification processes, particularly in Africa. The degradation of drylands has led to changes in local, regional, and even global climate. In the driest areas, increased albedo associated with degradation leads to cooling which can stabilize the atmosphere and reduce precipitation. In other drylands, desertification reduces soil moisture, and this change in surface hydrology leads to a warming that accelerates evapotranspiration and further reduces soil moisture levels. The nations of the world recognize the severity of the desertification issue, and most have ratified the “United Nations Convention to Combat Desertification in Countries Experiencing Serious Drought and/or Desertification, Particularly in Africa”.