In its "Living Planet" report, which is published every two years, WWF establishes an index for the "ecological footprint" of humans, and an assessment of the state of natural resources including plant and animal life, and the state of forests and oceans.

The report indicates that there is about 1.9 hectares (4.7 acres) of productive land and sea area available for each human being, but each human is occupying an ecological footprint about 2.3 hectares (5.7 acres), based on a worldwide average.

The report's overall "Living Planet Index" which is derived from survival trends over the past 30 years of hundreds of species of mammals, fish, birds and reptiles, declined by about 37 percent between 1970 and 2000.

"This is a devastating result of what humanity does to the biosphere," Claude Martin, director general of WWF International told journalists.

WWF estimates that human beings are running a huge deficit in terms of renewable resources and living off "natural capital" at a rate that is 20 percent above the earth's capacity to regenerate plant life, or absorb the environmental damage.

It predicts that by 2050, humans will consume between 180 percent and 220 percent of the earth's biological capacity unless governments take urgent action.

"We're calling this state ecological overshoot, because humanity has overshot the biological capacity of the earth's ecosystems, and we can only live on natural capital for so long," Jonathan Loh, author of the WWF report said.

WWF pinned most of the blame on wealthy or industrialized countries, largely due to their energy consumption.

The United Arab Emirates tops the footprint ranking with each of the UAE's former trucial states taking up more than 10 hectares, followed by the US, Canada and New Zealand.

"The per capita footprint of a European is about half that of their US counterpart," Loh noted.

Mozambique, Burundi, Bangladesh and Sierra Leone are at the bottom of the list, with less than 0.5 hectares occupied by each inhabitant.

Humans are fishing in the world's oceans faster than fish can reproduce, consuming wood products faster than tropical forests can be replanted or grow again and emitting carbon dioxide in much larger quantities than plant life or the atmosphere can absorb, according to WWF.

The biggest species decline over a 30-year period to 2000 involved populations of freshwater species, which have dropped by 55 percent.

The marine species population has dropped by about 35 percent, while forest species have declined by 15 percent over the same period, according to WWF.

The organization said the data indicated that "the world is currently undergoing a very rapid loss of biodiversity comparable with the great mass extinction events that have previously occurred only five or six times in the earth's history."

(China Daily July 10, 2002)