A new study published in the Oct. 30, 2013, issue of the journal Nature led by Manuel Delgado-Baquerizo of Universidad Pablo de Olavide in Spain that included a global collaboration of scientists reported that a changes in the chemical composition of the Earth’s dryland areas will reduce those areas ability to grow food crops and support the populations that depend on them.
The researchers examined the chemical composition over time of 224 dryland areas that are spread across the world. Dryland areas usually receive between 100 and 800 millimeters of rainfall per year. The small amount of rainfall is sufficient to produce crops and feed 38 percent of the Earth’s population. Drylands comprise about 41 percent of the Earth’s surface.
The researchers found that more arid conditions that have resulted from climate change have shifted the chemistry of the Earth’s drylands. The drylands are not expected to be capable of sustaining food crops by 2080 at the earliest and 2099 at the latest.
The reduction in atmospheric water of five to 15 percent has produced an increased rate of erosion that produced a higher than “normal” phosphorous content in all the drylands studied. The high phosphorous content will eventually prevent food crops from being grown in the Earth’s drylands.