FARM OF THE FUTURE

Join the BBC's Planet Earth III film crew and go behind the scenes in the city farm that's transforming fields into towers and running almost everything with robots

- CERI PERKINS

Stepping through the heavy, air-locked door into the world's most advanced indoor vertical farm, it's the noise that hits you first. It's loud. Machines buzz and whir over the insistent drone of the warehouse-scale air circulation system.

The lights are dazzling. Peering up at the two-storey-high living curtains of plants quickly prompts a protest from your neck. Nearby, a few workers, wearing coveralls, hair nets, hard hats and earplugs, keep a cool eye on their busy robot underlings. The air is bright with the fresh, sweet scent of tender young salad leaves.

It's a far cry from the story-book picture of a farm; there's no mud, no wellies, no hens pecking in the yard. But the owners of this facility, a San Francisco-based company called Plenty, claim the system they're pioneering inside this warehouse in Compton, Los Angeles, can produce up to 350 times the yield compared to a field of the same size. What's more, they say their system uses just 10% of the water and zero pesticides - and that it can be replicated almost anywhere.

The new farm in Compton grows four types of leafy greens: baby rocket, crispy lettuce, baby kale and curly spinach, and has the potential to produce up to two million kilograms of food annually, in the space of a single city block. If it lives up to its promise, the approach could revolutionise the way humanity feeds itself. That's why the crew filming the "Humans" episode of Planet Earth III was on site a day after the farm began operating. so that audiences around the world could see for themselves.

The episode takes an unflinching look at the effect our species is having on the planet. "The biggest challenge facing the natural world from the human world, right now, is habitat loss," explains producer-director Fredi Devas. "And the biggest area of habitat destruction comes from agriculture."