A group of German scientists led by Klaus Becker of the University of Hohenheim believes that planting drought-tolerant vegetation in arid regions could capture CO2 and mitigate the effects of climate change. In an article published in the July edition of Earth System Dynamics, the team identifies the species Jatropha curcas as the ideal tree for their method of “carbon farming”. The tree is able to withstand high temperatures, and it can flourish in coastal desert regions when supplied with desalinated seawater. The scientists posit ares in Egypt, India and Madagascar as the best locations for cultivation.
Carbon farming offers a less expensive alternative to other energy-intensive and costly geoengineering techniques. Costs range from about $57 to $83 per ton of CO2 mitigated. One hectare of Jatropha curcas has the ability to capture twenty five tons of CO2 a year over a twenty year period. To give an idea of scale, a plantation covering only three percent of the Arabian desert has the potential to to absorb all of Germany’s motor emissions within a couple of decades, and there are currently one billion estimated hectares available for carbon farming.
“From our point of view, afforestation as a geoengineering option for carbon sequestration is the most efficient and environmentally safe approach for climate change mitigation. Vegetation has played a key role in the global carbon cycle for millions of years, in contrast to many technical and very expensive geoengineering techniques,” says Becker.
The team hopes that their research will result in a pilot project. Their main challenges lie in the lack of studies concerning the effect that carbon farming has on local climates, the amount of salt the practice deposits in desert soil, and how greening desert regions affects the ecosystem.