Five mass extinctions have occurred in Earth’s history, and many experts have warned that a The sixth mass extinction could already be underway As a result of human activity since the Age of Discovery. Some scholars even suggested that Nearly 40% of the species (Opens in a new tab) The current inhabitants of our planet could become extinct as early as 2050.
But is this just a worst case scenario? It is such a dramatic drop in a landIs it likely to happen?
Death toll rises
The sixth mass extinction is certainly plausible, said Nick Rawlins, director of the Otago Palaeogenetics Laboratory and chief lecturer on Antiquity. DNA in the Department of Zoology at the University of Otago, New Zealand.
“I think it’s very likely,” Rawlins told Live Science in an email. “And if species do not become extinct globally, it is possible that those species that cannot adapt to our rapidly changing world will undergo range shrinkages, population bottlenecks, local extinctions, and functionally become extinct. The current extinction crisis may not have reached the top of the Big Five, but it certainly is. They are on the right track if nothing is done to stop them.”
According to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species (Opens in a new tab)about 41,000 – nearly a third of all assessed species – are currently threatened with extinction.
Many known species and subspecies – including the Sumatran orangutan (I put Abel), Amur leopard (tiger tiger), Sumatra the elephant (The largest Sumatran elephant), black Rhino (They are called Dhul-Qarnayn), hawksbill sea turtle (Eretmochelys imbricata)Sunda Tiger (Panthera Tigris Sundica) and Cross River Gorilla (Gorilla Gorilla Daily) – are classified as “critically endangered,” meaning they are critically endangered in the wild, according to both the IUCN and WWF (Opens in a new tab) (WWF).
The IUCN describes endangered as (Opens in a new tab) A category that contains those species that have a very high risk of extinction as a result of a rapid population decline of 80 to more than 90 percent over the past 10 years (or three generations), a current population of less than 50 individuals, or other factors .”
Many of these species are so critically threatened that they may not reach the year 2050. For example, only 70 Amur tigers remain in the wild, while the vaquita (Fukuina Bay), a type of porpoise believed to be the rarest marine mammal in the world, and has been reduced to only 10 individuals, According to WWF (Opens in a new tab).
There are countless lesser known species that are also endangered. 2019 review published in the magazine biological conservation (Opens in a new tab) It found that more than 40% of insect species are now threatened with extinction, with researchers stating that “more sustainable and environmentally based practices” need to be adopted across the board in order to “slow or reverse current trends, allow the recovery of insect population declines, and protect insect services.” The vital ecosystems they provide.”
Dozens of insect species are listed by the IUCN “Endangered,” including the white-headed grasshopper (Chorthippus acroleucus), south alpine bush-cricket (Anonconotus Apennines), the blue Swanepoel butterfly (Lepidochrysops swanepoeli), Franklin bumble bee (Franklini BombusAnd the land of Seychelles without wingsFusiform Procytettix).
The same terrible prediction of a steep decline is present in nearly all life on Earth. According to the 2018 report (Opens in a new tab) By the Intergovernmental Panel on Climate Change (IPCC), more than 90% of the world’s population Coral reefs It could die by 2050 even if global warming remains at 2.7°F (1.5°C). Latest IPCC (Opens in a new tab) However, the report was more incriminating, suggesting that by the early 2030s, a global temperature increase of 1.5°C could result in “99% of the world’s coral reefs experiencing heat waves too frequent to recover from.”
According to a 2022 report published in the magazine temper nature (Opens in a new tab)two out of five amphibians (40.7%) are now threatened with extinction, while a 2016 report published by the journal Biology Letters (Opens in a new tab) He stated that by 2050, 35% of frogs in the humid tropics of Queensland, Australia “could be committed to extinction”. In fact, the fall of amphibians is likely to be more pronounced. Scientists acknowledge that there are many amphibians that they have struggled to gather detailed information about, and these species are classified as data-deficient (DD). According to a report published in 2022 in the magazine communication biology, (Opens in a new tab) “85% of DD amphibians are under threat of extinction, as well as more than half of DD species in many other taxonomic groups, such as mammals and reptiles.”
Therefore, it is very difficult to determine the exact number of species that are likely to become extinct by 2050, in large part because the scale of extinction has not yet been determined. Furthermore, we do not know how many species there are currently, which makes it impossible to identify all the organisms that are at risk.
This is partly because “taxonomy — the science of naming biodiversity — is severely underfunded,” Rawlins said. “We can’t say how many species are going extinct if we can’t name biodiversity (or name it fast enough before it goes extinct).”
While extinctions occur naturally – More than 99% of all types (Opens in a new tab) Ever already extinct – human activity can dramatically speed up the rate of species extinction – an idea close to Rawlins’ home, New Zealand.
“The island’s ecosystems are the perfect example to illustrate this,” he said. “It is isolated and often has high levels of endemism (i.e., unique wildlife).” Rawlins said New Zealand has gone from about 230 bird species at the time of human arrival to about 150 today — resulting in a loss of about 80 bird species.
Many species can, if given time, adapt to climatic changes and changes in their natural habitat. 2021 research piece in the magazine Trends in ecology and evolution (Opens in a new tab) I’ve found that some animals “turn their shapes” to handle them better Climate changeSome birds seem to be the most adaptable. According to research, over the past 150 years, many species of Australian parrots have evolved to have increased beak size, an adaptation that allows them to better regulate their internal temperature.
But as human activity accelerates from climate change and habitat destruction, it is likely that some of the most vulnerable species will bear the brunt and find themselves unable to adapt.
What can he do?
With so many species currently in danger of extinction, is there anything we can do to prevent the worst case scenario?
For example, Rowlance said, “The conflict between short-term political gains and long-term funding for conservation initiatives must be resolved.” “A lot of endangered species survive only because of intense conservation management. If government and public will and resources are eroded, the situation will be very different.”
There are, of course, a large number of organizations, researchers, and projects on a mission dedicated to slowing or even halting climate change associated with humans. Climeworks (Opens in a new tab), a Switzerland-based company, is a leader in CO2 air capture technology, and aims to build a suite of facilities capable of removing CO2 from the air forever. Its first factory opened in Iceland in 2021.
in another place, Withdrawal from the project (Opens in a new tab)Founded in 2014, is a non-profit organization that seeks to connect experts around the world so that they can propose concepts and test them to stumble. greenhouse gases In the atmosphere of climbing, we will eventually see them retreat, while Bill Gates supports him Experiment with controlled perturbation in the stratosphere (Opens in a new tab) He is currently evaluating the feasibility of spraying non-toxic calcium carbonate (CaCO3) dust into the atmosphere, in an effort to reflect sunlight and thus offset – or significantly reduce – the effects of global warming.
Meanwhile, Rollins said, we need to look to the past to inform the future of the planet.
“To save the biodiversity we have left, we need to know how it has responded to past and present climate change and human impact, so that we can predict how it will respond in the future backed by evidence-based conservation management strategies,” he said. .
In short, more research and hard work is needed – before it’s too late.
Originally published on Live Science.