Can the planet handle China's new two-child policy?

China has ended its one-child rule but, with an ever-increasing need for resources, it's unclear if the world can sustain the expected population growth

China has a knack for world-changing policy shifts, whether it's devaluing its currency, launching a national carbon cap-and-trade system or, most recently, changing its decades-old restriction on how many children its citizens can have.

The country's decision to ease its one-child decree has raised some serious questions about sustainability. Right now, China consumes about half the cement, steel, aluminum and pork produced in the world. If it allows its citizens to have more children - and presumably use more resources - what will that mean for humanity's collective wellbeing and its pressing quest for sustainability?