(July 28, 2015) The world’s deserts may be storing some of the
climate-changing carbon dioxide emitted by human activities, a new study
suggests. Massive aquifers underneath deserts could hold more carbon than all
the plants on land, according to the new research.
Humans add carbon dioxide to the atmosphere through fossil
fuel combustion and deforestation. About 40 percent of this carbon stays in the
atmosphere and roughly 30 percent enters the ocean, according to the University
Corporation for Atmospheric Research. Scientists thought the remaining carbon
was taken up by plants on land, but measurements show plants don’t absorb all
of the leftover carbon. Scientists have been searching for a place on land
where the additional carbon is being stored—the so-called “missing carbon
sink.”
The new study suggests some of this carbon may be
disappearing underneath the world’s deserts – a process exacerbated by
irrigation. Scientists examining the flow of water through a Chinese desert
found that carbon from the atmosphere is being absorbed by crops, released into
the soil and transported underground in groundwater—a process that picked up
when farming entered the region 2,000 years ago.