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The Nine Challenges to Food Security That Threaten Our Ability to Feed the Cities

In my second post arising from the International Conference on Vertical Farming and Urban Agriculture being held yesterday and today at Nottingham University, I report on professor of ecology, Tim Benton, University of Leeds, work on addressing the food security challenges facing us. How will we feed the cities in the future?

Food Dont Waste It US FDA poster from 1917(Right: Food – Don't Waste It – an American FDA poster from 1917 displayed by Benton as evidence we have come full circle, and remembered nothing from history.)

Benton defines food security as meaning that everyone should have daily access to affordable nutrition; he considers that a lack of this led partly to the Arab Spring uprisings.

He lists  challenges to food security:

  1. In the UK and elsewhere food banks exist because of social inequalities; the poorer members of society don't have access to proper nutritious food and suffer poor diets leading to health problems.
  2. On a wider scale, the FAO forecasts that global food demand will increase by 60% by 2050, especially as more meat is eaten, and, globally, the size of the middle class grows. It's a sad fact that cities produce more food waste than rural areas.
  3. Then, he says, there are the supply chain logistics – the huge growth in food miles. One consequence of the global nature of the food industry is an increasing amount of homogeneity in diet around the world. This increases food insecurity.
  4. Then, there is the challenge of climate change. Right now we're on course for a 4oC world by 2100. This frightening prospect means that climate variability increases and by 2100 agriculture will be massively damaged and changed. Mapping the world's calorie production areas onto those most heavily impacted by this level of climate change shows that they coincide alarmingly.
  5. Globally there is already no more land for agriculture. We are down to 0.7ha/person agricultural land, from 2ha 100 yrs ago.
  6. Food, when imported, brings water with it. About 60% of food is water. This water is being taken from some parts of the world to other parts. This increases water scarcity.
  7. The economics don't add up. £9billion of public money in the UK is spent on agriculture, to feed an economy of £170bn. But from this must be subtracted the healthcare costs of poor eating – £30billion, or £2,500 per household. The environmental cost of nitrate pollution from fertilisers is £333.61/ha.
  8. Cities promote poor diets: 50% of Chinese are pre-diabetic and overconsumption is associated with >20% of deaths globally.
  9. They also waste food: the total food production of sub-Saharan Africa is equivalent to what Europe and North America throws away every year.

In conclusion, Jevon's paradox (the observation that greater energy efficiency, while in the short-run producing energy savings, may in the long-run result in higher energy use) also applies to the food system.

So, says Benton, we need sustainable nutrition: less waste, same cost, more healthy, repair the ecosystems.

From a political perspective this is not attractive. To politicians, he says, it's seen as expensive and a middle class fad. But then if you incorporate the external costs into the equation it can be seen as economically attractive despite the higher land and labour costs in rich countries for producing food.

Vertical growing unit on display at the conference.This, says Benton, is where does urban agriculture (UA) and vertical farming (VF) fit in.

(Right: Vertical growing unit on display at the conference.)

"Indoor growing lets you create resilience against climate extremes," he says. "We need to provide more habitats for people to grow their own, as they will respect it more. People will be reconnected with the land, nature and the seasons. UA creates skills and awareness, it's also good for community cohesion and health. They'll never grow enough to feed themselves but the benefits are enormous and many."

Vertical farming company Alterus has built a greenhouse on a roof of a parking garage in Vancouver that includes a proprietary system of stacked and growing trays. Urban growing needs to become more hi-tech so much more innovation is required.

Seawater greenhouses are possible and happening, on coasts in hot, dry countries (I describe these in in my book Solar Technology).

"So we need to find ways to increase the demand for food that does all these things," believes Tim.

"It's early days yet. The energy and infrastructure costs of VF must be brought down. Demand will help to do this and stimulate innovation."

I will post more articles about the conference during this week. Next will be a case study of commercial vertical farming.

This is part of a series of articles covering the International Conference on Vertical Farming and Urban Agriculture. They include: