The different populations of wild animals have lost on average 73% of their individuals in 50 years, mainly because of humanity which finds itself threatened, according to the reference report of the World Wide Fund for Nature (WWF) published Thursday , a few days before COP16 Biodiversity in Colombia.
This conclusion of the report Living planet does not mean that more than two-thirds of the number of wild animals on the planet have disappeared, but that the size of various populations (groups of animals of the same species sharing a common inhabitant) has decreased by 73% on average over the over the last fifty years (1970-2020).
The trend was 68% in the previous edition in 2022.
In total, around 5,500 vertebrates (mammals, birds, fish, reptiles and amphibians), distributed in some 35,000 populations across the world, are now listed by this “Living Planet Index”, established and updated every two years by the Society. Zoological Museum of London (ZSL) since 1998.
The index has become an international reference for taking the pulse of natural ecosystems and analyzing the consequences on human health, food or climate change, despite repeated criticism from scientists against the calculation method, accused of greatly exaggerating the extent of the decline.
“We remain confident in the solidity” of the index, replied Andrew Terry of the ZSL during a press briefing, highlighting the complementary use of a “series of indicators on the risks of extinctions, biodiversity and ecosystem health to broaden the bigger picture.”
Tipping points
“It’s not just about wildlife, it’s about the essential ecosystems that support human life,” warned Daudi Sumba, WWF’s chief curator, during an online presentation.
The new edition of the report reiterates the need to jointly confront the “interconnected” crises of climate and nature destruction. And emphasizes the growing threat of “tipping points” in certain ecosystems.
“The changes could be irreversible, with devastating consequences for humanity,” warned Mr. Sumba, citing the example of the Amazon, at risk of switching from the role of “carbon sink to carbon emitter, thereby accelerating global warming.
Another example: the loss of corals would alter the regeneration of fish species victims of overfishing and, in turn, would deprive humanity of precious food resources.
In detail, the strongest decline is observed in the populations of freshwater species (-85%), followed by terrestrial (-69%) and marine vertebrates (-56%).
“We have emptied the oceans of 40% of their biomass,” recalled Yann Laurans of WWF France.
Continent by continent, the decline reached 95% in Latin America and the Caribbean, followed by Africa (-76%), Asia and the Pacific (-60%).
The reduction is “less spectacular in Europe and Central Asia (-35%) and in North America (-39%) but only because large-scale impacts on nature were already visible before 1970 in these regions: certain populations have stabilized or even expanded thanks to conservation efforts and the reintroduction of species,” explains the report.
“Worrying”
The European bison, which disappeared in the wild in 1927, numbered 6,800 individuals in 2020 thanks to “large-scale breeding” and successful reintroduction, mainly in protected areas.
“The picture painted is incredibly worrying,” said Kirsten Schuijt, executive director of WWF.
“But the good news is that we are not yet at the point of no return,” she added, citing ongoing efforts in the wake of the Paris climate agreement or the Kunming-Montreal agreement. The latter set around twenty nature conservation objectives for States around the world to achieve by 2030.
Stimulating the implementation, so far timid, of this road map will be the main task of the 16th conference of the United Nations Convention on Biological Diversity (CBD) which takes place from October 21 to 1er November in Cali, Colombia.