According to new research , published by Proceedings of the National Academy of Sciences ( PNAS ) , increasing the use of groundwater may lead to greater political instability . Biofuels require : large amounts of irrigation typically from groundwater , which is slowly replaced ; and large tracts of land , taking up valuable storage space , which can be used to grow food .
According to new research, published by Proceedings of the National Academy of Sciences (PNAS), increasing the use of biofuels may lead to greater political strife. Biofuels require: large amounts of irrigation typically from groundwater, which is slowly replaced; and large amounts of land, taking up valuable farming space, which could be used to grow food.