“Over the last decade, world grain reserves have fallen by one third. World food prices have more than doubled” according to Lester R. Brown of the Earth Policy Institute in his book ‘Full Planet, Empty Plates’.
Current global population is 7.2 billion, by 2050 this is projected to rise to 9.6 billion. Also increasing the demand for food crops is the rise in biofuels (“the owners of the world’s 1 billion motor vehicles are pitted against the world’s poorest people for grain” says Brown) and growing appetites for meat- associated with rising affluence (because the conversion of grain into meat involves significant energy loss).
Nearly 1/3 of the world’s cropland is being lost to wind and water. Overgrazing and overcultivation strip protective layers of vegetation, leaving soil vulnerable to erosion. The United Nations estimates that 18 million acres of forest are lost every year- and agriculture is the leading cause. Only 31 percent of the Earth is now forested and the pressure to clear more and more land is great (especially considering the power-dynamics between the rich countries with insatiable appetites for resources and the poor countries with the lions share of undeveloped land). Not only are poor countries clearing land to grow crops they can sell but importing countries have acquired land in other countries to cultivate themselves. There is at present at lack of comprehensive information on these ‘land grabs’ but a 2009 World Bank report found that much land was being set aside for biofuels, industrial and cash crops with only 37 percent purchased on which to grow food. Along with our forests we are losing biodiversity and altering hydrological cycles; but forests are also natural carbon-stores so clearing them releases emissions that intensify global warming.
The average amount of food one person consumes in a day takes 2,000 litres of water, ‘Full Planet, Empty Plates’ states “70 percent of world water use is for irrigation”. Most growth in irrigated areas was traditionally fed by surface sources such as dams and rivers but by the 1970s such opportunities were pretty much exhausted so the emphasis shifted to underground sources. Significant fossil aquifers that will never refill are being depleted at an alarming rate and the majority that are replenished are being pumped at a rate greater than they can recover. Despite the massive proportion of our water use that goes to irrigation, irrigated land only accounts for 40 percent of food production, the rest is rainfed. Unfortunately climate change is responsible for creating instability that is regularly destroying entire crops in entire regions. With a half life of 5730 years the carbon we’ve been busily spewing into our atmosphere since the Industrial Revolution is going nowhere and being at the highest concentration for at least 800,000 years (research from the British Atlantic Survey shows) we have no reference for what to expect- other than that a continued reliance on consistent, predictable weather for farming would be unwise.
But there are solutions, some are very simple such as incentivising farmers to adopt integrated approaches to their work- such as growing shade loving varieties of cocoa in Ghanian forests rather than clearing land or eating less meat (which is not happening globally but is in the U.S. which is a fairly reliable indicator of future global trends). Some are a little more high-tech than this and vertical farming is one. Vertical farming can be incorporated into residential architecture or commercial/industrial taking the form of skins around buildings or making use of rooftops, it is a great utiliser of space in small holdings- as well as occupying dedicated futuristic ‘towering gardens of Eden’ (Dickson Despommier). Some use soil, many use hydroponic systems with nutrient enriched water, or aquaponic systems that make their own nutrients via fishtank. Larger farms take advantage of conveyor belts that carry the plants around the area so that each plant gets the same amount of Sunlight. Pesticides are unnecessary inside and many vertical farms follow sustainable and environmentally friendly practices throughout their work in keeping with the ethics of their operation.
In Linkoping, Sweden, Plantagon are building the International Centre of Excellence for Urban Agriculture, a ‘2001: A Space Odyssey’-esque monolith which will be a working vertical farm for scientists to test new technologies. In Vancouver, Alterrus supply a number of local restaurants with a farm on the roof of a car park. Producing 68 tonnes of leafy green vegetables and herbs a year, it requires only 10% of the water required in traditional farming and produces considerably higher yields.
Laurie Chetwood designed the winning entry to The Worshipful Company of Chartered Architects’ and The Royal Institute of British Architects’ ‘London Bridge competition’ with an inhabited London Bridge. The architects website explains that “it includes solar-powered spires, housing a self sufficient hydroponic organic farm and commercial centre taking advantage of renewable energy generation, harvesting and efficient re-use of water, solar heating and natural ventilation’. The commercial centre consists of a public and a wholesale fresh food market, cafes, restaurants and residential accommodations.
Vertical farms can help to feed people. This is so important. Even in the UK we have families depending on food banks and prices won’t stop rising. And, they can help to ease up demand for our precious land. And, they can cut carbon emissions exponentially. This is what we need to pursue.
Laurie Chetwood’s Inhabited London Bridge