This article in Water Resources Research says we have a shot at meeting future food demand.

Sustainable options for decreasing food demand and for increasing production include reduction of food losses on both the producer and consumer ends, elimination of unsustainable practices such as prolonged groundwater overdraft, closing of yield gaps with controlled expansions of nutrient application and irrigation, increases in crop yield and pest resistance through advances in biotechnology, and moderate expansion of rain fed cropland. Calculations based on reasonable assumptions suggest that such measures could meet the food needs of an increasing global population while protecting the environment.