Cooling Crops

Cooling Crops
by Jessica Kraft
March 2009

http://wholelifetimes.com/2009/03/oor_crops0903.html

Confronted with an exponential increase in atmospheric carbon dioxide, many scientists are looking into global-scale solutions to slow climate change. Some of these “geo-engineering” schemes sound far-fetched, such as the plan to build a giant solar reflector in space that will divert the sun’s rays from our warming planet. But recently, researchers in the U.K. have come upon a solution that could be much easier to implement — increasing the albedo of our agricultural lands.

Albedo is the reflective capacity of a surface, and certain plant species have a higher albedo than others. If we could switch out the low-reflecting crops for high-reflecting ones, we could potentially cool the atmosphere by one degree in certain food-producing regions, like the middle latitudes in the Northern hemisphere. This may not sound like much, but it would nearly reverse the trend of warming that has occurred over the last 150 years in these areas. The waxy, glossy leaves of some barley plants, for instance, reflect significantly more sunlight away from the earth’s surface, without affecting the plant’s ability to photosynthesize or produce grain. Certain species could be genetically modified to grow shinier foliage, adding to the cumulative cooling effect across the globe. With careful replacement, the new crops could yield the same amount of food, thereby maintaining global food production.

The technique of increasing albedo has already been implemented on a micro level in cities that experience a “heat island effect,” or a jump in local temperature due to low albedo. The more reflective a surface is — light-colored cars, white or silver roofs, even bald heads — the cooler the surrounding temperature will be. So to the farmers plowing their soil with shiny seedlings — off with your hats!