A team of researchers led by the Washington State University has found that deserts may play a key role in alleviating the effects of global warming.
The researchers, which included biologists from the WSU and scientists from the Desert Research Institute, have discovered that arid areas such as deserts can absorb large amounts of carbon. Deserts comprise some of the largest ecosystems on Earth and the latest findings can be used to gain a better understanding of how carbon is distributed throughout the planet. While the biggest problem with carbon emissions is the carbon floating around in the Earth's atmosphere, some of this carbon is stored in oceans and on land. The researchers published their findings in the online journal Nature Climate Change.
"It has pointed out the importance of these arid ecosystems," said WSU professor of biological sciences R. Dave Evans. "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." Evans also specializes in ecology and global change.
The long-term study took around 10 years to complete and the findings may prove to be important in terms of calculating the total amount of CO2 stored in land masses.
Since arid areas only get a small amount of rain each year, they are often very dry and can be relatively devoid of life compared with forests or grasslands. However, arid areas comprise almost 50 percent of the total land area on the planet. Due to the sheer area involved, deserts absorb more CO2 than forests. While forests can actually absorb more CO2 per square mile, forested areas only comprise around 31 percent of the planet's land area.
To figure out how much carbon arid areas can store, the researchers went to the Nevada National Security Site. The scientists then partitioned a plot of land into nine octagonal plots. Each plot has a diameter of around 75 feet and the scientists varied the conditions for each octagonal plot. Three of the plots received air with 380 parts per million (ppm) of CO2 while another three plots received air with 550 ppm of CO2. The former represents the current concentration of CO2 in the air today while the latter represents the predicted concentrations of CO2 in the year 2050. The last three plots served as the control group and did not receive any extra air.
"I was surprised at the magnitude of the carbon gain that we were able to detect it after 10 years, because 10 years isn't very long in the life of an ecosystem," said Evans.
After analyzing the results, the researchers found that there is a possibility that deserts may actually increase their carbon absorption capabilities to take in approximately 15 percent to 28 percent of the total carbon absorbed by land masses. Moreover, the increasing levels of CO2 emissions may actually increase the CO2 absorption of arid areas to offset around 4 percent to 8 percent of the current CO2 emission levels.
"Land is extremely valuable," said Evans. "A lot of growth may occur in these areas that are fairly arid and we don't know what that's going to do then to the carbon budget of these systems."