Does the solution to climate change lie in the middle of the Arabian desert, and a poisonous, but hardly plant called Jatropha curcas? Well, according to a group of scientists from Germany, it does. They want to build massive plantations in arid regions, and reckon about 2.5 billion acres could be enough to sequester all the carbon dioxide emitted since the Industrial Revolution.
That's right. Two and a half billion acres.
Led by Klaus Becker, at the University of Hohenheim, the researchers outline the plan in the latest edition of the journal Earth System Dynamics. They calculate that one hectare (about 2.5 acres) could capture 27.5 tons (25 metric tons) of CO2 a year for as long as 20 years. Covering 3% of the Arabian desert would absorb all the CO2 from vehicles in Germany over the same period, they say.
Jatropha curcas grows almost without any water at all, but grows better if you give it something. So the scientists want to ship in desalinated water from the ocean. For this reason, they reckon "carbon farming would work best nearer coasts." The paper models plantations from Egypt, India and Madagascar, and they hope to conduct trials in Oman or Qatar.
There are a few reasons to be skeptical, obviously. For one, jatropha has been hailed a miracle-worker before. During the first biofuels boom, in 2007, several start-ups planned massive crops, thinking the the plants would be turned into lots of energy with very little agricultural input. Then, they realized it wasn't that simple. More broadly, there are all kinds of geo-engineering schemes out there—from pumping tons of sulfur into the atmosphere, to dumping lumps of iron sulfate into the ocean—and they're not all, well, workable. (There's something about climate change that makes scientists want to think big, and not in a good way).
On the other hand, the Germans reckon the method would be competitive with the currently most feasible method: carbon capture and sequestration (CCS), which involves pumping CO2 underground, rather than letting it reach the atmosphere. They reckon carbon farming would cost between $56-84 per metric ton of CO2, and some of that could be recouped if the plants were harvested for fuel. Moreover, there could be side-benefits to developing desert regions, if current living areas become too dense.
Who knows? Maybe the future really does lie in Arabia?