Cities Absorb More CO2 Than Previously Estimated, Study Says

A new UK study says that cities and towns provide a large and underestimated amount of carbon storage, and can soak up even greater amounts of CO2 if city groups and gardeners plant more trees. Using satellite data and information collected during visits to locally owned or managed properties — including playing fields, golf courses, and abandoned lands — researchers from the University of Kent calculated that the city of Leicester, located in central England, stores about 231,000 tons of carbon, about 10 times more than previous estimates. “Currently, once land in the UK is considered to be urban, its biological carbon density is assumed to be zero,” said Zoe Davies, a Kent researcher and lead author of the study published in the Journal of Applied Ecology. “Our study illustrates this is not the case.” The planting of more trees is critical in expanding the size of carbon storage, Davies said. In Leicester, for example, most of the publicly controlled land is grassland. But if trees were planted on 10 percent of that land, the city’s carbon storage would increase by 12 percent. Currently, about 4 percent of the planet’s land surface is considered urbanized.