By Zoe Tabary
OSLO - Faced with the twin challenges of rapid population growth and rising carbon emissions, cities have no choice but to "go circular" and cut waste while using fewer resources, researchers and policymakers said on Thursday.
The amount of materials the world uses has tripled since 1970 and could double again by 2050 if no action is taken, the United Nations estimates.
From Rotterdam to Singapore, cities are looking at how they can shift to a circular economy, which means reusing products, parts and materials, producing no waste and pollution, and using fewer new resources and energy.
"If we don't change the way we produce and consume, we can continue dreaming about eradicating poverty and climate change," said Janez Potocnik, co-chair of the U.N.'s International Resource Panel and former EU Commissioner for the Environment.
"The circular economy is the oldest concept on Earth: in nature nothing is lost and everything has its purpose," Potocnik said at the Urban Future conference in Oslo, Norway's capital.
Miranda Schnitger, cities project lead at the Ellen MacArthur Foundation, which was set up by record-breaking British sailor Ellen MacArthur, said the circular economy "has to start with cities".
According to the United Nations, cities will host two-thirds of the world's people by 2050.
"Cities are already consuming 75% of global natural resources, account for 60-80% of carbon emissions - and that's before urban populations grow further," Schnitger said.
She cited office space – "60% of which is unused during the daytime" – and traffic as two aspects of city life that are particularly wasteful and polluting.
"Ninety percent of air pollution in cities comes from vehicle emissions, but most of the time there's one person in the car, not five, and the car is parked," she said.
"So you have to ask, how do we use that resource more efficiently?"
Some cities are advocating for sustainable fashion, an industry where the Ellen MacArthur Foundation estimates that less than 1% of clothing is recycled.
In Hong Kong, for example, a company called Green Baby collects, repairs and resells secondhand baby clothes, toys and accessories – and helps teenage and single mothers into work by employing them across the business.
But going circular also means regenerating natural systems in and around cities, said Schnitger, pointing to Singapore, which has developed 72 extra acres of vegetation by greening the rooftops of buildings.
David Berg, managing director of Circular in Rotterdam, a municipal initiative to minimise waste, said cities need to think creatively to get citizens on board.
For example, Rotterdam uses golden waste trucks to "tell residents that waste is worth gold", he explained, adding that the city aims to become waste-free by 2050.
City planners should create regulation that incentivises businesses and citizens to go circular, said Potocnik.
Ultimately, "the circular economy is unavoidable", he said.