Hot, arid regions aren't the kind of place people usually farm. But a team of German scientists wants to change that in a bid to help cool down global warming.
The idea is simple: plant the weedy shrub known as jatropha in hot, dry lands around the globe. Based on data from existing plantations, each hectare of jatropha would capture 25 metric tons of CO2 per year while growing.
Given roughly 1 billion hectares of such land available for such plantations, that's 25 billion metric tons removed from the air, or enough to offset the annual CO2 pollution of China, the U.S. and the E.U. combined. And it could be kept up for 20 years or so. The research appears in the journal Earth System Dynamics. [K. Becker et al., Carbon farming in hot, dry coastal areas: an option for climate change mitigation]
There's several catches of course. The poisonous jatropha would still need water to grow on this marginal land, and that is obviously hard to come by in arid regions. And land-grabbed jatropha plantations have had bad results growing the oil-seed crop for biofuels.
Regardless, the German scientists would like to set up a pilot plantation to test the scheme. Given the scale of the climate challenge, a few more shrubs can't hurt, and they just might help.
[The above text is a transcript of this podcast.]