ScienceDaily: In the concrete jungle at the core of a city, carbon dioxide (CO2) emissions are dominated by the fossil fuels burned by the dense concentrations of cars and buildings. Boston University researchers now have shown, however, that in metropolitan areas surrounding the city core, plant roots and decomposing organic material in soil give off enough CO2 , in a process termed "soil respiration," to make an unexpectedly great contribution to total emissions. In fact, analyzing CO2 released from soil respiration...