Deserts Absorb More Carbon dioxide than Previously Assumed [Video]
Scientists have found that deserts of the future could act as a major sink and help cut atmospheric carbon dioxide levels.
The study, conducted by researchers at Washington State University and colleagues, shows that arid regions will become major players in carbon absorption in the future. The research is expected to give scientists a better understanding of carbon uptake by land surfaces.
According to the researchers, rising carbon dioxide levels could lead to arid areas absorbing 4 to 8 percent of current emissions.
"It has pointed out the importance of these arid ecosystems," said R. Dave Evans, a WSU professor of biological sciences specializing in ecology and global change. "They are a major sink for atmospheric carbon dioxide, so as CO2 levels go up, they'll increase their uptake of CO2 from the atmosphere. They'll help take up some of that excess CO2 going into the atmosphere. They can't take it all up, but they'll help."
Carbon sinks are natural systems that absorb more carbon dioxide than they release. Forests and oceans are two main carbon sinks; they suck nearly half of the carbon dioxide released by human activities.
Forests store carbon in plant matter. However, arid regions outsize forest areas, meaning that in the future deserts could hold a large portion in earth's carbon budget.
The study results are based on a 10-year experiment conducted at the Mojave Desert. Researchers marked off nine octagonal plots. Each plot was about 75 feet in diameter. The team used PVC pipes to blow air with varying concentrations of carbon dioxide. Three plots received air with 380 parts-per-million concentrations of CO2, which is the current concentration of the gas. Three other parts were exposed to 550 parts per million, which is the level of the gas expected in 2050. Three other plots didn't receive any extra air.
The study suggests that deserts might increase carbon uptake in the future and account for as much as 15 to 28 percent of the gas currently absorbed by land. In other words, arid lands of the future will take up more carbon dioxide than was previously expected. The study did not account for other effects of climate change such as variation in rainfall and temperature.
The activity of a micro-organism-rich area called rhizosphere around the roots of plants was associated with increased carbon uptake in the experiment, researchers said.
The study was funded by U.S. Department of Energy's Terrestrial Carbon Processes Program and the National Science Foundation's Ecosystem Studies Program. It is published in the journal Nature Climate Change.