A snippet from the above National Geographic link -
"The potential number of Chinese people who could become consumers in the future is enormous," Mastny said. "Think about what that means in terms of availability of resources and the environmental impact."
Take cars, for example. In the 1980s there were virtually no private cars in China. In 2003 there were 14 million. In 2015 China will have an estimated 150 million cars.
"This is unsustainable," Mastny said. "We're not blaming China. It's just that if all the countries that are entering the consumer society try to emulate the patterns of the United States and other countries, clearly there is not going to be enough [resources] to go around."
I've heard that it would take 12.5 Earths to sustain human life if everyone on earth consumed as much as the average American consumes. It's happening folks.