Farming is moving indoors, where the sun never shines, where rainfall is irrelevant   and where the climate is always right. The perfect crop field could be inside a windowless building with controlled light, temperature,humidity,air quality and nutrition. It could be in a New York high- rise or a complex   in the Saudi desert. It may be an answer to the world's food problems. The world already is having trouble feeding itself. Half the people on Earth live in cities, and nearly half of those - about 3 billion - are hungry or ill-fed. Food prices, currently increasing, are badly affected by dryness, floods and the cost of energy required to plant, harvest and transport it. And prices will only get more unstable. Climate change makes long-term crop planning uncertain. Farmers in many parts of the world already are using water available to the last drop. And the world is getting more crowded: by mid-century, the global population will grow from 6.8 billion to 9 billion. To feed so many people may require expanding farmland at the expense of forests and wilderness, or finding ways to greatly increase crop output. Gertjan Meeuws and three other Dutch bioengineers grow vegetables and house plants in closed and regulated environments. In their research station, water flows into the pans when needed, and the temperature is kept constant. Lights go on and off, creating "day" and "night", but according to the rhythm of the plant. Meeuws says a building of 100 square meters and layers of plants could provide a daily diet of 200 grams of fresh fruit and vegetables for the entire population of Ken Bosch, about 140,000 people. Their idea isn't to grow foods that require much space, like corn or potatoes. Sunlight is not only unnecessary but can be harmful. Plants need only specific wavelengths of light to grow. Their growth rate is three times faster than under greenhouse conditions. They use about 90 percent less water than outdoor agriculture. And city farming means producing food near the consumer, so there's on need to transport it long distances. What is the purpose of the text ?
To compare traditional and indoor farming. To discuss the influence of climate change. To explain the world's food problem. To introduce a new model of farming.