‘Shiny’ crops offer solution to regional warming?

New research in Current Biology suggests that bio-engineering crops for greater reflectivity could result in a reduction in temperature across some regions of the globe, although at a price.

Researchers examined the impact on regional temperature of growing crops with a greater albedo – surface reflectivity – in areas already under cultivation. They conclude that by choosing crops with extra-reflective surface foliage; eg. barley with waxy leaves or sorghum with a hairy coating, temperature in Europe, Central Asia and North America could be reduced by 1 C in the summer. This could amount to a reduction in regional warming by one fifth of the level projected.

However, altering the climate across this latitudinal band may have a negative impact on other areas of the globe. A regional reduction in temperature will reduce water loss from plants, and soils which are therefore more moist. It could however also result in a shift in rainfall patterns, and increased instances of drought in Australia and the sub-tropics.

Bio-engineering in this way has the potential to offer a cheap and relatively simple way to reduce regional warming, and its associated health impacts. Selective breeding could lead to increased albedo in crops, therefore amplifying this effect. However, it is clear that this does not offer a realistic alternative to efforts to tackle warming on a global scale and decision-makers considering this as an option would have to think extremely carefully about the impact of this policy on other regions.

Ridgwell, A., Singarayer, J.S., Hetherington, A.M., Valdes, P.J. (2009). Tackling Regional Climate Change By Leaf Albedo Bio-geoengineering. Current Biology. 19: 1-5.