The Living Planet Index (LPI) is an indicator of the state of global

biological diversity Biodiversity is the variability of life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and phylogenetic diversity. Diversity is not distributed evenly on Eart ...

, based on trends in

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

populations of species from around the world. The

Zoological Society of London The Zoological Society of London (ZSL) is a charity and organization devoted to the worldwide animal conservation, conservation of animals and their habitat conservation, habitats. It was founded in 1826. Since 1828, it has maintained London Zo ...

(ZSL) manages the index in cooperation with the

World Wide Fund for Nature The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named th ...

(WWF). As of 2022, the index is statistically created from journal studies, online databases and government reports for 31,821 populations of 5,230 species of mammal, bird, reptile, amphibian and fish.

Results

According to the 2022 report, monitored wildlife populations show an average decline of 69% between 1970 and 2018, suggesting that natural ecosystems are degrading at a rate unprecedented in human history The extent of declines varies with geographic region, with monitored vertebrate populations in Latin America and the Caribbean experiencing average declines of 94%. One of the key drivers of declines has been identified as land-use change and the associated

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

and degradation, often linked to unsustainable agriculture, logging, or other development.

Calculation

The Living Planet Database (LPD) has been available online since 2013, and has been maintained by ZSL since 2016. The LPD contains more than 30,000 population trends for more than 5,200 species of fish, amphibians, reptiles, birds and mammals. The global LPI is calculated using these population time-series, which are gathered from a variety of sources such as journals, online databases and government reports. A generalized 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. This process uses a weighted geometric mean method which places most weight on the largest (most species-rich) groups within a biogeographic realm. This is done to counteract the uneven spatial and taxonomic distribution of data in the LPD. The three system indices are then averaged to produce the global LPI.

Criticism

The fact that "all decreases in population size, regardless of whether they bring a population close to extinction, are equally accounted for" has been noted as a limitation. In 2005, WWF authors identified that the population data was potentially unrepresentative. As of 2009, the database was found to contain too much bird data and gaps in the population coverage of tropical species, although it showed "little evidence of bias toward threatened species". The 2016 report was criticized by a professor at

Duke University Duke University is a Private university, private research university in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present-day city of Trinity, North Carolina, Trinity in 1838, the school moved to Durham in 1 ...

for over-representing western Europe, where more data were available. Talking to ''National Geographic'', he criticised the attempt to combine data from different regions and ecosystems into a single figure, arguing that such reports are likely motivated by a desire to grab attention and raise money. A 2017 investigation of the index by members of the ZSL team published in '' PLOS One'' found higher declines than had been estimated, and indications that in areas where less data is available, species might be declining more quickly. In 2020, a re-analysis of the baseline data by

McGill University McGill University (French: Université McGill) is an English-language public research university in Montreal, Quebec, Canada. Founded in 1821 by royal charter,Frost, Stanley Brice. ''McGill University, Vol. I. For the Advancement of Learning, ...

showed that the overall estimated trend of a decline by 60% since 1970 was driven by less than 3% of the studied populations; when some outliers of extreme decline are removed, the decline still exists but is considerably less catastrophic, and when more outliers (roughly amounting to 2.4% of the populations) are removed, the trend shifts to that of a decline between the 1980s and 2000s, but a roughly positive trend after 2000. This extreme sensitivity to outliers indicates that the present approach of the Living Planet Index may be flawed. A 2024 study by

Charles University Charles University (CUNI; , UK; ; ), or historically as the University of Prague (), is the largest university in the Czech Republic. It is one of the List of oldest universities in continuous operation, oldest universities in the world in conti ...

focused on calculation method, found that calculation of the Living Planet Index is biased by several mathematical issues, leading to overestimation of vertebrate population declines. When those mathematical issues are fixed, the majority of studied vertebrate populations shows balanced decline and growth (the only exception are the populations of

amphibians Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

, where the numbers show steady decline).

Publication

The index was originally developed in 1997 by the

(WWF) in collaboration with the World Conservation Monitoring Centre (UNEP-WCMC), the biodiversity assessment and policy implementation arm of the

United Nations Environment Programme The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong, its first director, after the Declaration of the United Nati ...

. WWF first published the index in 1998. Since 2006, the

(ZSL) manages the index in cooperation with WWF. Results are presented biennially in the ''WWF Living Planet Report'' and in publications such as the

Millennium Ecosystem Assessment The Millennium Ecosystem Assessment (MA) is a major assessment of the human impact on the environment, called for by the United Nations Secretary-General Kofi Annan in 2000, launched in 2001 and published in 2005 with more than $14 million of ...

and the UN Global Biodiversity Outlook. National and regional reports are now being produced to focus on relevant issues at a smaller scale. The latest edition of the ''Living Planet Report'' was released in October 2022.

Coverage

The index is often misinterpreted in the media, with incorrect suggestions that it shows we have lost 69% of all animals or species since 1970. This widespread misinterpretation has led to several articles being published which detail what the LPI does and doesn't show, and how to correctly interpret the trend.

Convention on Biological Diversity

In April 2002, and again in 2006, 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 Biodiversity loss happens when plant or animal species disappear completely from Earth (extinction) or when there is a decrease or disappearance of species in a specific area. Biodiversity loss means that there is a reduction in Biodiversity, b ...

at the global, regional and national levels…" The LPI played a pivotal role in measuring progress towards the CBD's 2010 target. It has also been adopted by the CBD as an indicator of progress towards its Nagoya Protocol 2011-2020 targets 5, 6, and 12 (part of the Aichi Biodiversity Targets). Informing the CBD 2020 strategic plan, the Indicators and Assessments Unit 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 An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

References

External links

*
LPI at GitHub
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