The diversity of living things on earth has been decreasing dramatically for years. A new analysis of around 15,000 plant and animal species in Europe now shows that the extent is greater than expected: around a fifth of them are threatened with extinction. Extrapolated worldwide, this would correspond to twice as many species as previously estimated. According to the analysis, the greatest threat to these species is the intensification of agriculture. The loss of species also has serious consequences for us humans, warn the scientists.
Biodiversity is decreasing worldwide. More and more species are threatened with extinction. Some governments and nonprofit organizations are trying to reduce biodiversity loss, but with limited success. To do this better, they need to know as much as possible about the threats to different species in different locations. In order to deepen this understanding, a team led by Axel Hochkirch from the National Museum of Natural History Luxembourg has now analyzed all 14,669 species of European animals and plants that were listed in so-called red lists by the end of 2020. These lists from the International Union for Conservation of Nature (IUCN) indicate the threatened status of the species listed and are considered the most comprehensive source of biodiversity and threat status. But they are far from complete. The species examined in the new study correspond to around ten percent of all animals and plants that occur on land and in water in Europe.
One in five species in Europe is threatened with extinction
The researchers found that around 19 percent of the species examined are threatened with extinction, including 27 percent of plants, 24 percent of invertebrates (e.g. bees, butterflies, dragonflies and grasshoppers) and 18 percent of vertebrates (amphibians, birds, fish, mammals and reptiles). A total of 2,839 of the species examined are threatened with extinction in Europe. However, extrapolated to all species worldwide, the scientists say there are significantly more.
“Our analysis suggests that two million plant and animal species are at risk of extinction,” the authors report. This result is twice as high as the most recent IPBES assumption from 2019, according to which one of a total of eight million known species worldwide is threatened with extinction. In particular, the proportion of invertebrates threatened with extinction is far higher than previous estimates of this international organization on biodiversity. Since the last IPBES analysis, new data has been available which has now been incorporated into the new study and has led to the new findings.
“The new study shows much more clearly and comprehensively than before that significantly more species are threatened with extinction. This makes the dimension and urgency of improved protection of these species more than clear,” says biodiversity researcher Matthias Glaubrecht from the University of Hamburg, who was not involved in the study. He also points out that, although patchy, the best data is still available from Europe. “If the situation is so dramatic here, this means that the biodiversity crisis in other, much more species-rich regions is very likely to be even more explosive - especially in the tropical areas that are still insufficiently researched, such as in Asia and Africa,” says Glaubrecht .
The main threat is humans
The analysis confirms that the European biodiversity of flora and fauna is threatened primarily by changes in agricultural land use by us humans. The scientists explain that the land is being farmed more intensively and more one-sidedly. As a result, habitats are lost, biological resources are overused and the environment is polluted. At the same time, agricultural areas are increasingly being converted into residential and commercial areas.
According to the researchers, the results could be used to measure the progress of efforts to protect biodiversity. But they also call for further measures and investments in these efforts because biological diversity is also in the interest of us humans: it is crucial for food security, the creation of wealth and the future well-being of the European population. “The study shows what is at stake – the survival of many species that we also need to survive,” says Glaubrecht. At the end of 2022, the final declaration of the Kunming-Montreal Conference (COP15) set the goal of stopping human-caused species extinction by 2030 and reducing the extinction rate and risk for all species tenfold by 2050.
Source: Axel Hochkirch (National Museum of Natural History Luxembourg) et al., PLOS ONE, doi: 10.1371/journal.pone.0293083