Animals at home on the range in Danish zoo project
The human population is projected to hit nine billion by 2050. That makes Harvard scientist Dr E.O. Wilson's recent proposal that we devote half of the planet to wildlife to avoid a "biological holocaust" on the scale of the dinosaurs' extinction appear fanciful.
But a step in the direction of overturning humans' woeful exploitation of other species has been taken by Denmark's Bjarke Ingels Group (Big). The Copenhagen-based architects have suggested a radical rethink of the traditional zoo in the Danish town of Givskud.
Built in the 1960s, the zoo already features a "drive-through" safari park-style attraction - but the plans for its overhaul, envisaged by Ingels, will realise something entirely different.
"It's a question of trying to create successful cohabitation between humans and other species," says Ingels. "We have designed lots of condos and other housing for humans, but to have new species to design for is interesting, because different animals behave differently.
"Some can be contained with simple measures, whereas others are Houdinis and can escape from almost anything."
Containment and making a break for it would seem to be distant concerns, however, given Ingels' vision for what will become known as Zootopia when it opens in 2019, on the zoo's 50th anniversary. Free of pens, cages and concrete enclosures, the animals will roam across 120 hectares of crafted wilderness without suspecting they are being watched, says Big.
Human intrusion will be prevented by use of hiding places, reversing the usual dynamic of visitor and "inmate", and extending that sensation of openness in the animals' habitat that characterises, for example, Singapore Zoo.
"We're looking at ways to hide the barriers between people and animals," says Ingels, "and we've tried to eliminate all traces of human architecture.
"You'll see rolling hills over the areas where the lions will retreat in the Danish winter. Changes in water levels in trenches will stop other animals crossing; and your cable car might go close to the bears below without being in range."
So while avoiding any potential Jurassic Park-style confrontations, "the human experience is going to be much more exciting" than in the zoos and safari parks of old.
A private enterprise supported by Denmark's Ole Kirk's Foundation, Zootopia will be a "completely different type" of attraction to Copenhagen Zoo, which recently killed Marius the giraffe, followed by two lions and their cubs, all of which were healthy but which didn't fit the zoo's breeding requirements.
It will also present a remarkable spectacle on entry, with paying customers arriving in something that looks like a giant, tilted crater, with views over the entire landscape of Zootopia. From the crater there will be three gates to take you to America, Asia or Africa.
And in a sci-fi touch, some of the artists' impressions of Zootopia depict guests travelling through this reinvented Eden in gleaming, mirrored capsules. It all represents a brave new world for those previously subjected to the likes of the miserable experience that is Saigon Zoo, with its stressed tiger, psychotic, chained elephants and monkeys imprisoned in concrete cages.
Not that Hong Kong, with its claustrophobic Botanical Gardens and almost non-existent animal-welfare laws, has much to shout about either.
Free range would seem to be the future - and not just for chickens.