Humanity would need five Earths to produce the resources needed if everyone lived as profligately as Americans, according to a report issued Tuesday.
As it is, humanity each year uses resources equivalent to nearly one-and-a-half Earths to meet its needs, said the report by Global Footprint Network, an international think tank.
"We are demanding nature's services -- using resources and creating CO2 emissions -- at a rate 44 percent faster than what nature can regenerate and reabsorb," the document said.
"That means it takes the Earth just under 18 months to produce the ecological services humanity needs in one year," it said.
And if humankind continues to use natural resources and produce waste at the current rate, "we will require the resources of two planets to meet our demands by the early 2030s," a gluttonous level of ecological spending that may cause major ecosystem collapse, the report said.