(Washington, DC)  --  A top government scientist says the world could face a serious food shortage in less than 40 years.  

Dr. Fred Davies with U-S-A-I-D says there will be a point when food production will be limited because of shortages of land, water and energy.  He warns that it could destabilize world politics.  

Davis said food production would have to increase by 70 percent to meet the demand of a 30 percent jump in human population by mid century.