Foreword

At the Earth Summit in Rio de Janeiro, world leaders committed themselves to the goal of sustainable development. The term sustainable development has since entered into everyday language, and yet it remains an elusive concept. Indeed, it is now used by governments, industry, and non-governmental organizations to mean almost anything they want it to mean. However, in truth, it is a very simple idea. Before the Rio Summit, WWF, along with our partner organizations IUCN The World Conservation Union and UNEP, published Caring for the Earth a report subtitled "A strategy for sustainable living". We defined sustainable development as "improving the quality of human life while living within the carrying capacity of supporting ecosystems", and this definition remains as valid today as it was then.

The years after Rio have seen improvements in the quality of life for people in many parts of the world, yet we continue to exact an unacceptable price from the Earth 's ecosystems at the same time. The past decade has witnessed fires on an unprecedented scale in the tropical forests of Brazil and Indonesia, coral bleaching that has left vast areas of reef in the Caribbean, Indian, and Pacific Oceans as ghosts of their former selves, the collapse of commercially valuable fish stocks in the Atlantic,the ecological devastation of the Black Sea, the Aral Sea, and Lake Chad, and the continual loss of precious wetland and freshwater ecosystems around the world.

What has this to do with sustainable development? We live on a bountiful planet, but not a limitless one. The Earth has a limited capacity to yield its renewable resources. Provided that this capacity is not diminished, the Earth will continue to provide food, materials,energy,and freshwater each year,in perpetuity,for the benefit of all humanity.

Ensuring access to basic resources and improving the health and livelihoods of the world's poorest people cannot be tackled separately from maintaining the integrity of natural ecosystems. We rely on the living biosphere to provide food, materials, water, and, importantly,to absorb carbon dioxide. By continuing to abuse the biosphere, and through the inequitable sharing of the Earth's resources, we undermine the chances of eradicating poverty, and put the whole of humanity under the threat of global climate change.

This report is about measuring human pressure on the Earth,and how that pressure is distributed among countries and regions. The Living Planet Index is a measure of the state of natural ecosystems, according to the abundance of animal species they support, while the ecological footprint compares countries' consumption of natural resources with the Earth 's biological capacity to regenerate them. These two measures do not take into account all of the conditions necessary to achieve sustainable development. But unless we recognize the ecological limits of the biosphere, we cannot claim to be sustainable.

Dr Claude Martin
Director General, WWF International