The United Nations (UN) predicts the world’s population will grow by some 2.5 billion people by 2050, and 80 percent of the world’s population will live in cities. At the same time, 80 percent of the land that is suitable for growing food is already in use. Moreover, extreme weather patterns across the globe have devastated crops, creating higher food prices, and as consumers become more conscious of how their food is produced, it is becoming more difficult for farmers to keep up with urban growth. This is driving innovation of new farming technologies that allow plants to grow without sunlight in indoor environments close to or within cities.
Source: http://www.lighting.philips.com/main/products/horticulture/city-farming