Living Planet Report 2004
The Living Planet Report is WWF's periodic update on the state of the world's ecosystems. This is measured using 2 main indicators. The first indicator is the fact that the Living Planet Index is derived from trends over the past 30 years in populations of hundreds of species of birds, mammals, reptiles, amphibians and fish. The Living Planet Index (LPI) is an indicator of the state of the world's biodiversity: it measures trends in populations of vertebrate species living in terrestrial, freshwater, and marine ecosystems around the world. The second indicator is a measure our human Ecological Footprint - this is the pressure placed by humans on these populations, and caused by our consumption of renewable natural resources.