Mountain areas within deserts are under particular threat, said the United Nations Environment Programme report.
Population growth and inefficient water use are, by 2050, set to move some countries with deserts beyond thresholds of water stress, or even worse, water scarcity. Examples include Chad, Iraq, Niger and Syria.
Renewable supplies of water, which are fed to deserts by large rivers, are also expected to be threatened, in some cases severely, by 2025.
Not all changes harmful
But not all the changes need necessarily be harmful. For example, most deserts have sunlight and temperature regimes that favour sites for shrimp and fish farms in locations such as Arizona and the Negev desert in Israel.
In addition, Nipa, a salt grass harvested in the Sonoran desert of north western Mexico, thrives on pure seawater producing large grain yields the size of wheat.
"It is a strong candidate for a major global food crop and could become this desert's greatest gift to the world," said the report.
Prime locations for aquaculture
Shafqat Kakakhel, UNEPs officer in charge and deputy executive director, cited the growing interest in deserts as prime locations for aquaculture and the source of novel drugs, herbal medicines and industrial products derived from plants.
Almost one-quarter of the earth's land surface some 33,7 million square kilometres has been defined as 'desert' in some sense. These deserts are inhabited by over 500 million people.
The desert cores remain pristine in many parts of the world, representing some of the planet's last remaining areas of total wilderness.
Most of the 12 desert regions, whose future climate has been modelled, are facing a drier future with rainfall in some cases forecast to be 10 to 20 percent lower by the end of the century.
Source: Decision News Media
Enviro Health Centre