The WWF's Living Planet Report 2004 shows that humans are now consuming 20 percent more natural resources than the Earth can produce. As a result, other species are being crowded out of existence.
The Living Planet Index, which tracks trends in populations of more than a thousand species, shows that half of all populations of freshwater species have disappeared between 1970 and 2000, and populations of terrestrial and marine species have dropped by 30 percent.
"We are spending nature's capital faster than it can regenerate," said Dr. Claude Martin, director general of WWF International. "We are running up an ecological debt which we won't be able to pay off unless governments restore the balance between our consumption of natural resources and the Earth's ability to renew them."
The Living Planet Report 2004 is the fifth in a series of Living Planet publications, which all explore the impact of humans on the planet. Based on two indicators - the Living Planet Index and the Ecological Footprint - it examines the state of nature and resource use in 149 countries.
Our ecological footprint - that is the impact of humanity on the Earth - has increased 2.5 fold since 1961, the report shows.
The average footprint today is 2.2 hectares per person while there is only 1.8 hectares of land to provide natural resources for each of the people on the planet.
To get this figure WWF divided the Earth's 11.3 billion hectares of productive land and sea space among its 6.1 billion people.
The ecological footprint is a measure of environmental sustainability. It measures how much nature we have, how much nature we use, and who gets what, WWF explains. It represents the amount of biologically productive land and water an individual, a city, a country or all of humanity requires for the resources it consumes and to absorb its waste, using prevailing technology.
WWF calls our energy footprint dominated by the use of fossils fuels such as coal, gas and oil "particularly alarming." This is the fastest growing component of the ecological footprint, increasing by nearly 700 percent in the 40 years between 1961 and 2001.
WWF warns that the overexploitation of these fuels is putting "the whole of humanity under threat from climate change." The antidote is found in renewable energies and promote energy efficient technologies, buildings and transport systems, the organization says.
Nowhere is this overconsumption more acute than in the United States and Canada. The ecological footprint of an average North American is not only double that of a European but seven times that of the average Asian or African.
Pressure on the Earth's resources will only increase as the Asian and African regions develop and consume more.
"Sustainable living and a high quality of life are not incompatible," said Jonathan Loh, one of the authors of the report. "However we need to stop wasting natural resources and to redress the imbalance in consumption between the developing and industrialized worlds."
WWF is urging governments to act on their commitments to reduce the rate of biodiversity loss by 2010. These commitments were repeated at the meeting of the UN Convention on Biological Diversity in Kuala Lumpur this year. The meeting also set national and regional targets for creating networks of protected areas, including new parks, which will help safeguard biodiversity.
The Living Planet Report 2004 is online at: www.panda.org/livingplanet.