sixth mass extinction

Averting a mass extinction

July 19, 2024 By EarthWise Leave a Comment

There has been widespread concern that biodiversity is under siege and that we are in the beginnings of a sixth mass extinction in the long history of the Earth, this time caused by the actions of humanity. There has been considerable debate about what can be done about it and solutions generally involve protecting large areas of the planet from human disruptions. Some countries have set a target of protecting 30% of land and sea.

A new study by a broad coalition of conservation organizations and published in Frontiers in Science, concludes that humans can preserve much of the great diversity of life on Earth by setting aside just 1.2% of the planet for protection.

The experts mapped the wilderness available to rare and threatened plants and animals. They then identified specific hotspots for rare wildlife that have yet to be protected. They found a total of 16,825 such sites which nevertheless all together add up an area smaller than the state of Wisconsin.

Some scientists have been warning that by focusing too much on the size of protected lands, we are not necessarily safeguarding areas that are especially rich in wildlife. The new study pushes for prioritizing hotspots for rare species, which the authors claim would be sufficient to stave off a sixth mass extinction. The truth is that most species on Earth are rare, meaning that they are few in number or cover a small range, or both.

The study estimated that the cost of protecting the identified hotspot sites would be $263 billion, which is certainly a large amount of money. But the authors point out that this sum to save global biodiversity is less than the yearly revenue of Shell Oil.

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To Avert a Mass Extinction, Protect 1 Percent of Earth

Photo, posted April 20, 2018, courtesy of Per Harald Olsen / AfricanBioServices via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Sixth Mass Extinction | Earth Wise

February 16, 2022 By EarthWise Leave a Comment

Extinction is a natural part of life. Plants and animals disappear all the time. When one species goes extinct, its place in the ecosystem is typically filled by another. The so-called normal rate of extinction is thought to be somewhere between 0.1 and 1 species per 10,000 species per 100 years.

A mass extinction event is when species disappear at a much faster clip than they can be replaced. By definition, mass extinction is when about three-quarters of the world’s species are lost in a short amount of time on a geologic scale, which is measured in millions of years.

There have been five previous mass extinction events throughout the history of life on earth. Today, many experts warn that a sixth mass extinction event is already underway – the first since dinosaurs were wiped out some 65 million years ago. While previous mass extinctions were the result of extreme natural phenomena like volcanic eruptions and asteroid strikes, this one is a result of human activities.

Researchers from the University of Hawai’i at Manoa and the National Museum of Natural History in France recently published a comprehensive assessment of evidence of this ongoing extinction event. The researchers estimated that since the year 1500, Earth could already have lost between 7.5% and 13% of the two million known species on Earth. This amounts to a staggering 150,000 to 260,000 species.

While mitigating the effects of climate change and reducing the rates of habitat loss would help, raising awareness of this crisis and its fallout for all life forms – including us – would be most effective in driving change.

The time we have to avoid dramatic consequences is rapidly running out.

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Strong evidence shows Sixth Mass Extinction of global biodiversity in progress

Photo, posted September 18, 2015, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Butterflies And Moths In A Changing World | Earth Wise

July 20, 2021 By EarthWise Leave a Comment

Extinction is a part of life. Plant and animal species disappear all the time. In fact, approximately 98% of all the organisms that have ever existed on planet earth are now extinct. Earth’s so-called ‘normal’ rate of extinction is thought to be somewhere between 0.1 and 1 species per 10,000 species per 100 years.

But anthropogenic climate change is bringing about rapid change in nature. Put more simply, human activity is killing nature at an unprecedented rate. According to many scientists, the earth’s sixth mass extinction has already begun. Mass extinctions are defined as times when the Earth loses more than 75% of its species in a geologically short interval.

The changing climate puts immense pressure on species for change. According to a new study by researchers from the University of Helsinki and the Finnish Environment Institute, the few butterfly and moth species capable of adjusting to the changing climate by moving up their flight period and moving further north have fared the best.

In Finland, researchers compared temporal shifts in the flight period and spatial shifts in the northern range boundary of 289 moth and butterfly species, as well as changes in abundance over a roughly 20-year period.

They found that about 45% of species that either moved northward or advanced their flight period fared much better than the roughly 40% of species that did not respond in either way. On average, the populations of these poorly responding species declined. But the 15% of species that did both had the largest increase in abundance.

The ability to adapt to a changing climate is going to be vital for species survival.

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Butterflies and moths have difficulty adjusting to a rapidly changing climate

What is mass extinction and are we facing a sixth one?

Photo, posted August 16, 2017, courtesy of Tero Laakso via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

How To Bend The Curve On Biodiversity Loss | Earth Wise

October 15, 2020 By EarthWise Leave a Comment

Biodiversity has been declining at an alarming rate in recent years as a result of human activities, including land use changes, pollution, and climate change. According to a 2019 UN report, one million species – out of an estimated eight million – are threatened with extinction. Many scientists warn we are in the middle of the sixth mass extinction event in Earth’s history. Previous mass extinction events wiped out up to 95% of all species and took ecosystems millions of years to recover.

Fortunately, new research indicates that it might not be too late to bend the curve on biodiversity loss. According to the report, which was recently published in the journal Nature, more ambitious conservation measures are needed in order to preserve biodiversity. In addition, more efficient food production and healthier and less wasteful consumption and trade are needed to bend the curve.

If these measures are undertaken with unprecedented ambition and coordination, the research team says the efforts will provide an opportunity to reverse biodiversity loss by 2050.

But even under the best case scenario, ongoing land conversion will lead to further biodiversity losses before the curve starts to bend. In fact, at least one third of projected losses in the coming years are unlikely to be avoided under any scenario. Biodiversity losses were projected to be highest in the regions richest in biodiversity, including South Asia, Southeast Asia, Sub-Saharan Africa, the Caribbean, and Latin America.

The study, which was led by the International Institute for Applied Systems Analysis in Austria, makes it clear that urgent action is needed this decade in order to have any chance of bending the curve.

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Curbing land clearing for food production is vital to reverse biodiversity declines

Photo, posted November 1, 2017, courtesy of Rod Waddington via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mammals Can’t Seem To Evolve Fast Enough

November 1, 2018 By EarthWise Leave a Comment

Our planet has been through five upheavals over the past 450 million years. During each one, the environment on earth changed so dramatically that most plant and animal species became extinct. After each of these mass extinction events, evolution slowly filled the gaps in the environment with new species.