London Zoological Society reports on health of planet Earth

October 24, 2006

The annual Living Planet Report compiled by the Zoological Society of London and the Global Footprint Network, published this week by WWF International, assessed "the health of the planet's ecosystems" and measured the demands people make on the planet's resources.

The Living Planet Index is based on population trends between 1970 and 2003 of over 3 600 populations of more than 1 300 vertebrate species from around the world. There has been an overall decline of around 30 per cent over the 33-year period. Tropical species populations declined by around 55 per cent on average from 1970 to 2003, while temperate species populations, have shown little overall change.

The Ecological Footprint measures the area of biologically productive land and sea required to sustian humanity. In 2003 this was 14.1 billion global hectares, or 2.2 global hectares per person (a global hectare is a hectare with world-average ability to produce resources and absorb wastes). The total supply of productive area, or biocapacity, in 2003 was 11.2 global hectares, or 1.8 global hectares per person. Demand overshot supply first in the 1980s and has been increasing every year since, By 2003 the overshoot was about 25 per cent. Thus, it took approximately a year and three months for the Earth to produce the ecological resources humanity used in that year.

The Living Planet Index and the Ecological Footprint, along with other measures, have been adopted as indicators for the 2010 targets of the Convention on Biological Diversity.

The report concludes with a description of the roles of the various disciplines required to "shift humanity's current trajectory on to a path that will remain within the biological capacity of the planet". James P. Leape, the Director General of WWF International summarises: "The message of these two indices is clear and urgent: we have been exceeding the Earth's ability to support our lifestyles for the past 20 years, and we need to stop. We must balance our consumption with the natural world's capacity to regenerate and absorb our wastes. If we do not, we risk irreversible damage".