British researchers are proposing an intriguing idea: That by planting the right kinds of wheat, we can affect how much light is being reflected back into space and thereby counteract global warming. The effect might cool swathes of North America and Europe by as much as one-degree Celsius in summer, with a world-wide average effect of .1 degree. That's a big number—about a fifth of the warming that has occurred in the last 100 years. (Estimates for Global Warming's effects by the year 2100 are typically about two degrees.)
The idea is the newest in a long line of geoengineering proposals that hope to fight global warming with massive attempts to re-engineer the environment. The ideas have ranged from sending mirrors up to space, to seeding the ocean with iron, feeding algae that consume carbon dioxide, and they've attracted fierce interest in the last couple years. But these proposals have quickly run into dire limitations: The iron seeding idea, for example, could produce disasterous side effects; larger projects seem prohibitively expensive.
But the new work, from Andy Ridgwell at University of Bristol, elegantly sidesteps those problems. It doesn't propose any great overhaul of what we already do—in North America and Europe, millions of acres of wheat are planted every year, so this wouldn't necessarily require a massive intervention with unknown technology or an unimaginably large engineering effort. Ridgwell simply proposes that we choose those varieties that reflect the most heat. He also suggests that eventually we might selectively breed wheat (as we've done for thousands of years) for its reflective properties, in addition to crop yield and hardiness. Perhaps that sounds too good to be true. Stay tuned.