Climate Central: With worldwide food production expected to double by 2050, it's almost inevitable that agriculture is going to have to expand in a warming world with a growing population. A new study suggests that if new farmland is created carefully, billions of tons of carbon emissions could be saved. In many places across the globe, new farmland is carved out of forests and other environmentally sensitive areas, the clear-cutting of which releases carbon into the atmosphere. When left intact, biologically diverse...