Maximum capacity of future Earth: 2 billion, ecologists say

Maximum capacity of future Earth: 2 billion, ecologists say

SAN FRANCISCO (UPI): Even if humans learn to make maximum use of the Earth's dwindling resources, by the year 2100 the planet will only comfortably sustain two billion people -- nearly four billion fewer than the current population.

In a year-long study that estimated the natural resources remaining by that time, Cornell University researchers determined that for everyone to live in "relative prosperity," the global population -- now numbering 5.6 billion -- would have to shrink to between one billion and two billion.

The U.S. population of 260 million would have to decrease to 200 million, David Pimentel, Cornell professor of ecology and systematics, said at the annual meeting of the American Association for the Advancement of Science.

"A drastic demographic adjustment to two billion humans will cause serious social, economic and political problems, but continued rapid population growth will result in even more severe conflicts -- plus catastrophic public health and environmental problems," Pimentel said, noting current projections place the 2100 population at 12 billion to 15 billion.