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human activity and the destruction of the planet

Sixth mass extinction of wildlife is accelerating: new study

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Prof. Gerardo Ceballos is an ecologist and conservationist very well-known for his theoretical and empirical work on animal ecology and conservation. He is particularly recognized by his influential work on global patterns of distribution of diversity, endemism, and extinction risk in vertebrates.

Image result for Gerardo Ceballos

Prof Gerardo Ceballos

It is his published work on the sixth mass extinction that led me to choose the title of my book “Three Generations Left: Human activity and the destruction of the planet”. In this paper, Ceballos and his colleagues who predicted that, unless we make changes to our way of life, we would be facing a sixth mass extinction of species within three generations. Now, he is suggesting, through new studies, that the mass extinction is happening even more quickly than that.

GoldenLion Tamarin

Golden Lion Tamarin – one of 500 species at risk of extinction

Several sources are quoting this new research, initially published in the Proceedings of the National Academy of Sciences journal.

https://www.pnas.org/content/early/2020/05/27/1922686117

The following summary can be found on the BBC website:

“Human impacts on the places on Earth with the most richness of life have brought hundreds of wild animals to the brink of extinction, a study shows.

The likes of logging and poaching have pushed 500 mammals, birds, reptiles and amphibians to the point where they’re hanging by a thread, research found.

This is yet more evidence that the world’s undergoing a sixth mass extinction, scientists argue. Species are disappearing at more than 100 times the natural rate, they say.

And unlike other mass extinctions, caused by volcano eruptions or asteroid collisions, we only have ourselves to blame.

Prof Gerardo Ceballos of the National University of Mexico in Mexico City, said regional ecosystems are facing collapse.

“We have entered the sixth mass extinction,” he told BBC News. “Based on our research and what we’re seeing, the extinction crisis is so bad that whatever we do in the next 10 to 50 years is what will define the future of humanity.”

Prof Ceballos worked on the study with two other well-known conservation scientists, Stanford University’s Prof Paul Erhlich, and Dr Peter Raven of the Missouri Botanical Garden in St Louis, US.

Using data from the International Union for the Conservation of Nature (IUCN) Red List of threatened species and Birdlife (the bird authority for the IUCN), they identified at least 515 species that are on the brink of extinction, with fewer than a thousand individuals left.

The animals are found on every continent save Antarctica, in places highly impacted by humans, primarily in the tropics and subtropics.

They include the Golden Lion Tamarin, Ethiopian Wolf, Javan Rhinoceros, Spanish Imperial Eagle, Yellow-eared Parrot, Gharial and Green Poison Frog.

The scientists describe the extinction crisis as an existential threat to civilisation, along with climate change and pollution, to which it is tied.

And they say they have a “moral imperative” to draw attention to the loss of biodiversity, which they say is still rather ignored by most people.

The research is published in the journal Proceedings of the National Academy of Sciences (PNAS).

Commenting, Prof Diana Fisher of the University of Queensland, Australia, said the study deserved attention because so many people don’t realise how much of the world’s wildlife faces impending extinction.

“I agree with the authors that this extinction crisis needs to be elevated to an emergency equal to climate change,” she said.

Prof Chris Johnson of the University of Tasmania said the current rate of extinction of species is higher than at any time since 66 million years ago, when the collision of a space-rock with the Earth killed off dinosaurs and many other species.

“Threats to species in today’s world – things like habitat destruction and climate change – are growing rapidly,” he said, adding that the 515 species down to 1,000 or fewer individuals are likely to be gone very soon.

And Prof Euan Ritchie of Deakin University in Australia said the study “is yet more dire confirmation that we are destroying life at a horrific pace and scale”.”


The Guardian report from Damian Carrington (1st June 2020) states that: “More than 500 species of land animals were found to be on the brink of extinction and likely to be lost within 20 years. In comparison, the same number were lost over the whole of the last century. Without the human destruction of nature, even this rate of loss would have taken thousands of years….

“The land vertebrates on the verge of extinction, with fewer than 1,000 individuals left, include the Sumatran rhino, the Clarión wren, the Española giant tortoise and the harlequin frog. Historic data was available for 77 of the species and the scientists found these had lost 94% of their populations.

“The researchers also warned of a domino effect, with the loss of one species tipping others that depend on it over the edge. “Extinction breeds extinctions,” they said, noting that unlike other environmental problems extinction is irreversible.

“Humanity relies on biodiversity for its health and wellbeing, scientists said, with the coronavirus pandemic an extreme example of the dangers of ravaging the natural world. Rising human population, destruction of habitats, the wildlife trade, pollution and the climate crisis must all be urgently tackled, they said.

“The analysis examined data on 29,400 land vertebrate species compiled by the IUCN Red List of Threatened Species and BirdLife International. The researchers identified 515 species with populations below 1,000 and about half of these had fewer than 250 remaining. Most of these mammals, birds, reptiles and amphibians were found in tropical and subtropical regions.

“Scientists discovered that 388 species of land vertebrate had populations under 5,000, and the vast majority (84%) lived in the same regions as the species with populations under 1,000, creating the conditions for a domino effect.”

 

ethiopian wolf2
Ethiopian wolf
harlequinfrog
Harlequin frog
Sumatran tiger
Sumatran Tiger
Photographs of other endangered species can be found in The New York Times article on this issue:


An analysis of the report from Vox.com outlines how the loss of one species can have an impact on other species, which are a part of a dependency web.

The researchers found that one extinction can cause ripple effects throughout an ecosystem, leaving other species vulnerable to the same fate. “Extinction breeds extinctions,” they write in their June 1 paper in the Proceedings of the National Academy of Sciences.

With the accelerating pace of destruction, scientists are racing to understand these fragile bits of life before they’re gone. “This means that the opportunity we have to study and save them will be far greater over the next few decades than ever again,” said Peter Raven, a coauthor of the study and a professor emeritus of botany at Washington University in St. Louis, in an email.

The findings also highlight how life can interact in unexpected ways and how difficult it can be to slow ecological destruction once it starts. “It’s similar to climate change; once it gets rolling, it gets harder and harder to unwind,” said Noah Greenwald, the endangered species director for the Center for Biological Diversity, who was not involved in the study. “We don’t know what the tipping points are, and that’s scary.”



 

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