Humanity's current demands on natural resources are unsustainable, according to the WWF's Living Planet Report. The environmental group's report says rich countries are using up the natural resources of poor countries in order to sustain excessive consumption.
Jim Leape, Director General of WWF International, says the Living Planet Report paints a worrying picture of the world's health.
"It tells us that we are using resources at a rate that is 50 percent faster than the earth can sustain," he said. "We are living as if we had one and a half planets to support us."
The report says humanity's demand on natural resources has doubled since 1966. But Leape says that strain on natural resources is coming mostly from the world's wealthiest countries. He says high-income countries have an ecological footprint five times bigger than low-income countries.
"In the simplest terms, the richest countries are consuming the natural capital of some of the poorest countries on earth," he said.
The WWF report is published in cooperation with the Zoological Society of London and the Global Footprint Network. It measures the health of almost 8,000 populations of more than 2,500 species.
The report found that current trends are very different between tropical and temperate climates. The health of biodiversity in the tropics has declined by 60 percent - but in temperate regions it has improved by 30 percent.
But in the world's poorest countries, Leape says biodiversity has fallen by more than 50 percent in recent decades.
International Union for Conservation of Nature researcher Dr. Jean-Christophe Vié says it is those poorest countries that tend to depend most on natural resources.
"People think probably in our developed world that we can live without nature and biodiversity, probably mostly people living in cities, but that is not the case," he said. "Most of the poorest people depend on what they can find around their house just for food, for example. So it is really very worrying that we are putting their basic resources under this level of stress."
According to the WWF report, the United Arab Emirates, United States, and Denmark are among the top 10 countries with the biggest ecological footprint. Government delegates are meeting in Japan later this month for the Convention on Biological Diversity to address the need to sustain biodiversity on earth.