fall in vertebrate populations, growing role of global warming… What to remember from the WWF’s “Living Planet” report

Lowland gorillas, lynx, sharks, corals… “The icons of biodiversity, as precious as they are essential to the balance of our ecosystems, are diminishing at an alarming rate.” The “Living Planet” report, published every two years by the WWF, takes stock of the situation global biodiversity and the health of the planet. In the latest edition, made public Thursday, October 13, the association is concerned of one “devastating drop” populations of vertebrates – fish, birds, mammals, amphibians and reptiles – around the world.

Arguing that “declines in abundance are early warning indicators of overall ecosystem health,” long calls on governments to adopt “an ambitious global agreement to save wildlife”on the occasion of the 15th Conference of Parties to the Convention on Biological Diversity (COP15), in Montreal, in December. But first, here are his conclusions.

69% of vertebrate animal populations disappeared between 1970 and 2018

It’s a “alarming figure”, commented the program director of the NGO, Arnaud Gauffier, on the occasion of the presentation of the report to the press on Monday : between 1970 and 2018, vertebrate populations fell by 69%. In its previous edition, published in 2020, the NGO quantified this average population decline – through its Living Planet Index, or “LPI” – 68%, compared to 50% in 2012. This index, calculated from scientific data collected over 32 000 populations over 5 230 vertebrate species, summarizes the variations in populations of animals monitored around the world. The higher it is, the more the species is threatened. Go from an LPI of 68% to 69% in two years, “it’s colossal“noticed Arnaud Gauffier. “The fact that this index is not improving is catastrophic in itself.”

The report points to examples of species “on borrowed time”, which have recorded a worrying decline since 1970 : the population of the eastern lowland gorilla has fallen by 80%, that of African forest elephants by 86%. Warm-water corals have lost 50% of their population, and oceanic rays and sharks are in decline by 71%, the report also reads.

Global warming increasingly threatens biodiversity

The destruction of habitats linked to the conversion of land for the benefit of agriculture and food, the overexploitation of species and resources, pollution, the introduction of invasive foreign species and global warming are the main threats that affect biodiversity. While land use change remains the main driver of biodiversity loss, global warming is playing an increasingly important role in the collapse of vertebrate species, warns the report.

“If we don’t limit warming to 1.5°C, climate change will surely become the main cause of biodiversity loss in the coming decades.”

WWF

in its 2022 “Living Planet” report

Climate crisis and biodiversity collapse “are two sides of the same coin”, still assures the WWF. The rise in average global temperature, which has risen by 1.2°C since the start of the industrial era, is already causing “mass mortality phenomena, as well as the first extinctions of species”, explains the report, for which “each additional degree should increase these losses”.

By way of example, the document cites in particular warm water corals. About half of them “disappeared for various reasons”explains the WWF, which fears that global warming will deliver the final blow. “A warming of 1.5°C will cause a loss of 70-90% of warm water corals and a warming of 2°C will cause a loss of more than 99%.”

Similarly, in France, leatherback turtles, present in particular in the strait of the Maroni River on the border between Guyana and Suriname, have seen their population collapse by 95%, under the combined effects of accidental captures linked to fishing. illegal and the rise in temperatures which unbalances the ratio between births of males and females. Also, “if we continue to approach these emergencies as two separate issues, neither will be effectively addressed,” hammers the report, which points to the role of ecosystems in the fight against global warming.

10 million hectares of forest disappear every year

Forests and other mangroves are essential carbon sinks, details the WWF. “Every year we lose about 10 million hectares of forests, an area equivalent to that of Portugal”, he warns, underlining the interdependence of climate and nature crises, highlighted by a first joint report by the IPCC and theIntergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)* – often referred to as “IPCC of biodiversity” – in 2021.

LONG also points out the benefits of acting in a coordinated manner on these two fronts : “Lhe protected areas managed by local communities show a flourishing biodiversity, the restoration of ecosystems by nature-based solutions is beneficial for biodiversity and also for the climate (…)”, she points out.

In this context, the WWF considers “essential to achieve the same degree of involvement [dans la lutte contre l’effondrement de la biodiversité] that we’re starting to see around climate action” and promotes the goal of a “positive nature balance by 2030”. The goal is to reverse the population curve within eight years, in order to “return to satisfactory levels of biodiversity in 2050”summarized the director general of the NGO, Véronique Andrieux, in front of the press, drawing the parallel with the “net zero” ambition required of climate actors.

Freshwater ecosystems are hard hit

Freshwater environments, which host “a rich biodiversity, including a third of vertebrate species”, are particularly affected by this degradation, with an average drop in populations established at 83%, according to the WWF.

To explain this situation, the NGO cites, among other things, pollution – such as pesticides, plastics or even industrial and agricultural waste –, water withdrawals or modification of flows, overexploitation of species, as well as the introduction of invasive species. “As freshwater environments are highly connected, threats can easily move from place to place”she explains in this report, which reports that the LPI of migratory freshwater fish shows an average decline of 76% between 1970 and 2016.

“Only 37% of rivers over 1 000 km are still ‘natural’ along their entire length”, highlights the report, and freshwater species, including migratory fish, collide with “the presence of dams and reservoirs [qui constituent] a threat to their survival. Thanks to the removal of two dams and the rehabilitation of other dams in a river in the northeastern United States, populations of alewife, river herring, have been able to recover, details the report. They passed “from a few hundred to almost 2 million in five years, which has allowed the resumption of fishing”.

Latin America is the most affected region

According to the WWF, the situation differs greatly from one ecosystem to another. Threats and their intensity also vary according to geographical areas. “Threats from agriculture, hunting and logging are mostly present in the tropics, while pollution hotspots predominate in Europe“, he explains. However, it is in Latin America-Caribbean that the average abundance of populations is experiencing the greatest regional decline, with an LPI of 94% between 1970 and 2018, warns the NGO. second place is Africa (66%), followed by Asia and the Pacific (55%), North America (20%) and finally Europe (18%).

In the Amazon, “The latest research indicates that we are dangerously approaching a tipping point beyond which our largest rainforest will no longer function”warns the report.

* This link is in English.