5.2.16 (HL)—Technological improvements

High-tech greenhouses and vertical farms control light, temperature, water and nutrients to produce high yields in limited space, increasingly close to urban consumers.

Potential benefits include land efficiency, controlled water delivery, year-round output and shorter urban supply chains; costs include capital, materials, technical dependence and energy for lighting, heating, cooling and pumping.

A vertical farm may grow more leafy vegetables per square metre, but fossil-fuel electricity can make its land-saving gain carry a large greenhouse-gas burden.

Compare yield, land and water use with energy source, emissions, capital, crop range and system reliability.

Land-efficient is not automatically energy-efficient or sustainable.