Crop breeding could stop CO2 increase 'stone dead'

A British scientist has calculated that breeding crops with deeper roots can draw down enough CO2 to stop the increase in Global Warming 'stone dead'. Carbon dioxide levels in the air have risen 40 percent to 390 parts per million (ppm) since the start of the Industrial Revolution and are growing about 2 ppm a year. "If you add an extra 2 ppm a year and you can effectively trap that by increasing the amount of roots by an equivalent amount, you can stop the increase stone dead. To take about 100 ppm from the atmosphere is highly feasible and that equates to an extra 100 tonnes per hectare on average for two years," says Professor Douglas Kell of the University of Manchester in the Annals of Botany journal. "Doubling root biomass to a nominal two meters is really the key issue, together with the longevity of the carbon they secrete and sequester below-ground." Previous studies have doubted the benefits of deep roots locking away large amounts of carbon. But this was because the studies did not take soil measurements much below a meter. "What matters is not so much what is happening now as what might be achieved with suitable breeding of plants with deep and reasonably long-lived roots. Many such plants exist, but have not been bred for agriculture," he says. Professor Kell calculated that even a 2 percent increase in soil carbon down to 2 meters could lead to an extra 100 tonnes of carbon per hectare if that carbon stays in the soil for at least two years, reports Reuters. Professor Kell have a carbon calculator that shows how much carbon could be sequestered depending on depth and percentage of carbon uptake over the total area of global crop and grasslands.The calculator can be found here.