The earth could become "unrecognizable" by 2050, if a growing global population with higher income keeps consuming more resources, researchers warned.
"By 2050 we will not have a planet left that is recognizable" if the global population continues to increase, said Jason Clay of the World Wildlife Fund Sunday at the annual meeting of the American Association for the Advancement of Science.
The United Nations has projected that the global population will reach seven billion this year, and climb to nine billion by 2050.
Meanwhile, as income is expected to rise over the next 40 years -- tripling globally and quintupling in developing nations, people tend to consume more meat, eggs or dairy products, which would cost more grains to produce, adding more strain to global food supplies.
Population experts called for more funding for family planning programs to help control the growth in the number of humans, especially in developing nations.
"We want to minimize population growth, and the only viable way to do that is through more effective family planning," said John Casterline, director of the Initiative in Population Research at Ohio State University.