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 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 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.