Living Planet Index
The Living Planet Index (LPI) is an indicator of the state of global biological diversity, based on trends in vertebrate populations of species from around the world.
The LPI provides the general public, scientists and policy-makers with information on trends in the abundance of the world’s vertebrates and offers insights into which habitats or ecosystems have species that are declining most rapidly. This information can be used to define the impact humans are having on the planet and for guiding actions to address biodiversity loss.
The World Wide Fund for Nature (WWF) is working in collaboration with the Institute of Zoology (IoZ), the research division of the Zoological Society of London (ZSL), to further develop the project which began in 1997.
The Living Planet Index was originally developed by WWF in collaboration with UNEP-WCMC, the biodiversity assessment and policy implementation arm of the United Nations Environment Programme. UNEP-WCMC collected much of the data for the index in the first few years of the project.
Results are presented biennially in the WWF Living Planet Report, on the World Wide Web, and in publications such as the Millennium Ecosystem Assessment and the UN Global Environment Outlook. National and regional reports are now being produced to focus on relevant issues at a smaller scale.
Between 1970 and 2007, the index fell by 28%. This global trend suggests that we are degrading natural ecosystems at a rate unprecedented in human history.
The current Living Planet Database (LPD) maintained by ZSL, contains over 10,000 population trends for more than 2,500 species of fish, amphibians, reptiles, birds and mammals.
The global LPI is calculated using over 7000 of these population time-series which are gathered from a variety of sources such as journals, online databases and government reports.
A generalised additive modelling framework is used to determine the underlying trend in each population time-series. Average rates of change are calculated and aggregated to the species level.
Each species trend is aggregated to produce an index for the terrestrial, marine and freshwater systems. The three system indices are weighted equally within tropical and temperate regions which are then aggregated to produce the global LPI.
Convention on Biological Diversity 
In April 2002, at the Convention on Biological Diversity (CBD), 188 Nations committed themselves to actions to: “… achieve, by 2010, a significant reduction of the current rate of biodiversity loss at the global, regional and national levels…”
The Living Planet Index is one of the indicators designated for immediate testing by the CBD as a means of measuring progress towards the 2010 target, specifically for trends in abundance and distribution of species. The work at ZSL is concerned with ensuring the most rigorous and robust methods are implemented for the measurement of population trends, expanding the coverage of the LPI to more broadly represent biodiversity, and disaggregating the index in meaningful ways (such as assessing the changes in exploited or invasive species).
Building the LPD network 
Population data invariably comes from the better monitored regions of the world; however a network of organisations collecting species population data is currently being developed. With the regular addition of high quality data to the LPD the LPI will provide greater coverage of species from poorly known taxonomic groups and regions. In addition, ZSL and WWF have recently begun forming partnerships to develop LPIs for Invertebrates and plants.
See also 
- Loh, J., Green, R.E., Ricketts, T., Lamoreux, J., Jenkins, M., Kapos, V., and Randers, J., 2005. The Living Planet Index: using species population time series to track trends in biodiversity. Phil. Trans. R. Soc. B. 360: 289–295.
- Loh, J., Collen, B., McRae, L., Holbrook, S., Amin, R., Ram, M., and Baillie, J. (2006) Living Planet Index. Living Planet Report (ed. By J. Loh & S. Goldfinger), WWF, Gland, Switzerland. (pdf)
- Collen, B., McRae, L., Kothari, G., Mellor, R., Daniel, O., Greenwood, A., Amin, R., Holbrook, S. and Baillie, J. (2008) Living Planet Index. 2010 and beyond: rising to the biodiversity challenge (ed. By J. Loh), WWF, Gland, Switzerland. (pdf)
- UNEP (2006) Report on the eighth meeting of the Conference of the Parties to the Convention on Biological Diversity In: CBD, editor. pp. 374.