Shinier Crops Could Help Lessen The Impact Of Climate Change, According To New Research.

Scientists say planting arable land with varieties whose leaves reflect more light back into the atmosphere could cut regional temperatures by as much as 1°C in summertime.

Many politicians have signed up to a goal of limiting warming to 2°C over pre-industrial levels, so this could be a very significant reduction in some regions and could buy societies time to cut CO₂ emissions and find other ways of dealing with the problem.

All plants reflect a certain proportion of the sunlight hitting them away from the Earth. But some reflect more than others. Those with a waxy outer coating on their leaves, or with variegated or hairy leaves, tend to be more reflective, and are said to have a higher 'albedo'. The arrangement of the leaves on the plant is also important. The researchers suggest replacing existing varieties of maize, for example, with higher-albedo alternatives.

The paper appears in Current Biology. Its authors suggest that replacing arable plants with alternatives that were around 20% more reflective would lower summer temperatures by around 1°C throughout much of central north America and Eurasia - equivalent to offsetting around a fifth of the seasonal warming in these regions that is expected to arise towards the end of the century from doubling the current level of atmospheric carbon dioxide.

The question is whether varieties are available that offer this improvement in albedo without compromising the other qualities farmers want, such as high yield, hardiness and resistance to disease. There's plenty of variation in most farmed species, though, so selective breeding or genetic modification could well produce such varieties even if they don't exist right now.

'Persuading farmers to do this would be critical. But if suitable varieties were available with a climate-friendly trait alongside all the other characteristics farmers are looking for, I see no reason why farmers shouldn't adopt them,' says Dr Andy Ridgwell, a Royal Society funded Earth scientist at Bristol University and one of the paper's authors.

He notes that such a shift could take place gradually and would not require huge initial investments, since crops are replanted every year as a matter of course. He suggests that existing agricultural subsidies could be changed to encourage farmers to shift to new varieties.