Roberts says “on a good day”, when temperatures outside are in the high 30s or low 40s, the temperature in her dugout is around 23 to 25C. “It’s like you’ve walked into an air-conditioned room.”
While extreme weather has forced Coober Pedy’s residents underground, it’s not the only place on Earth where authorities are looking beneath the surface for new urban space.
With two-thirds of the world’s population expected to live in cities by 2050, urban land is expected to become an increasingly limited resource. Many cities – due to space constraints, heritage areas, or other factors – cannot build up, or out. But what about down?
Consider the case of Singapore, one of the most crowded countries on the planet. Its population of nearly 5.5 million people is squeezed into a city state that covers just 710 sq km. “For Singapore, the main thrust for going underground is really to solve the land shortage issue,” says Singapore-based Zhou Yingxin of the Associated Research Centers for the Urban Underground Space, a non-governmental organisation of experts who design and analyse cities' subterranean spaces.
“Traditionally, we’ve tried to reclaim land by digging up the sea and buying sand, but that is becoming less and less viable – the sea is getting deeper, we’re getting to the boundaries, the sand is getting more expensive, our neighbours are complaining and all that.”
So, one plan currently on the table is an Underground Science City (USC). Designed to house a 300,000 sq m research and development facility 30-80m below the surface, the USC will support biomedical and biochemistry industries, among others. If completed, it is estimated to house a working population of 4,200.