This WW2 bunker is growing sustainable salad leaves deep underground. Here’s how

At the height of the Second World War, the British government built eight huge shelters deep under London. They protected Londoners from bombs, and now one of these bunkers has found a role in a new battle – the fight against climate change.

Thirty-three metres below the streets of Clapham, in south-west London, lies what was claimed at its launch to be the world’s first subterranean farm. It uses the latest hydroponic technology and LED lighting powered by renewable energy to produce fresh vegetables.

Growing Underground is the brainchild of two friends, Richard Ballard and Steven Dring, who set up their company Zero Carbon Farms in 2015. Today they have a hectare of underground growing space producing leafy greens, herbs like Thai basil and garlic chives and pea shoots.

The growing process is soil-free – plants are grown on recycled carpets – and the farm can produce up to 60 harvests a year, six times the output of a conventional outdoor farm. It uses 70% less water than growing similar crops in soil and is pesticide-free.

Focusing on supplying local people and businesses, the farm says that its produce goes from farm to fork in less than four hours. Growing Underground also supplies food retailers and doorstep delivery services.

Feeding our cities

The United Nations estimates there could be two billion more people on our planet by 2050 and global food production will need to increase by 70% to feed them. Ballard and Dring say underground farming is a good way to feed growing city populations.

Vertical farms using closed-loop hydroponics allow food production to expand even as rising urbanization causes water shortages, says the UN Food and Agriculture Organization (FAO). They also play a key role in delivering nutritious food to the poorest in society, the FAO says.

As well as reducing food miles by growing food where people live, underground farms are also immune from the impact of seasonal changes and weather events.

Agriculture and Forestry account for almost a quarter (23%) of human-induced greenhouse gas emissions, according to a report by the Intergovernmental Panel on Climate Change.

That’s something Zero Carbon Farms is determined to change. The underground farm is certified carbon neutral.

The World Economic Forum’s report, Incentivizing Food Systems Transformation, warns that a major change in the way we produce food is needed to establish an inclusive, efficient, sustainable, nutritious and healthy food supply for a growing global population.