Deserts turning green from rising carbon dioxide
A process called CO2 fertilization has helped arid regions around the world grow more green foliage over the past three decades.
Satellite observations, as well as research data from the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO) and the Australian National University (ANU), have found that a process called CO2 fertilization have led to an overall 11% growth in foliage in arid regions in North America, the Middle East, Australia and Africa between 1982 and 2010.
“In Australia, our native vegetation is superbly adapted to surviving in arid environments and it consequently uses water very efficiently,” said Dr Randall Donohue, leader of the research team, “Australian vegetation seems quite sensitive to CO2 fertilisation. This, along with the vast extents of arid landscapes, means Australia featured prominently in our results.”
Map of foliage changes over recent decades
The research results are not surprising, but this is the first time data proving CO2 fertilization has been compiled: “While a CO2 effect on foliage response has long been speculated, until now it has been difficult to demonstrate,” explains Dr. Donohue, “Our work was able to tease-out the CO2 fertilization effect by using mathematical modelling together with satellite data adjusted to take out the observed effects of other influences such as precipitation, air temperature, the amount of light, and land-use changes”
CO2 fertilization occurs when elevated levels of the gas cause leaves to extract more carbon and/or lose less water to the atmosphere during photosynthesis. If less water is lost by the tree, the tree responds by growing more leaves, leading to increased foliage that can be detected by satellites.
While the full effects of increased CO2 in the atmosphere need to be studied, the effects on foliage seem to be good, and would increase agriculture and forestry in such areas.