Planet's sixth mass extinction event is underway — humans are to blame

There have been five mass extinction events of biodiversity throughout the planet's history, but all have been attributed to natural phenomena
Planet's sixth mass extinction event is underway — humans are to blame

The world may have lost up to 260,000 species, or 13%, in the last 500 years as a human-led sixth mass extinction event currently takes shape.

The world may have lost up to 260,000 species, or 13%, in the last 500 years as a human-led sixth mass extinction event currently takes shape.

That is the sobering analysis from biologists at the University of Hawaii at Mānoa and the Muséum National d’Histoire Naturelle in Paris, as they examined whether or not another so-called 'mass extinction event' is currently taking place.

There have been five mass extinction events of biodiversity throughout the planet's history, but all have been attributed to natural phenomena.

Scientists have, in recent years, been exploring whether a new mass extinction event is happening at the moment — only this time driven by human activity, and not the natural cycle.

According to Britain's Natural History Museum, a mass extinction event is when species vanish much faster than they are replaced. 

This is usually defined as about 75% of the world's species being lost in a 'short' amount of geological time — less than 2.8m years, according to the museum.

Five previous periods have significantly altered the face of the planet, including the most recent Cretaceous event that occurred 65m years ago, killing 78% of all species, including the remaining dinosaurs that could not fly. 

This was most likely caused by an asteroid hitting the Earth in what is now Mexico, according to the Natural History Museum.

In the latest research, the biologists from Hawaii and Paris said: "Although considerable evidence indicates that there is a biodiversity crisis of increasing extinctions and plummeting abundances, some do not accept that this amounts to a sixth mass extinction. 

"Often, they use the IUCN Red List to support their stance."

The IUCN Red List stands for the International Union for Conservation of Nature Red List of Threatened Species, the world's biggest data inventory of the vulnerable species conservation status.

The researchers said only pointing to birds and mammals and ignoring invertebrates — creatures such as spiders, worms, and insects — meant the true picture was not being painted. 

By including invertebrates, the biologists were able to estimate that since around 1500, as many as 7.5% to 13%, or 150,000 to 260,000, of all 2m known species have already gone extinct, far greater than the 882, or 0.04%, on the IUCN Red List.

"Humans are the only species able to manipulate the Earth on a grand scale, and they have allowed the current crisis to happen ... we reaffirm the message that the biodiversity that makes our world so fascinating, beautiful, and functional is vanishing unnoticed at an unprecedented rate," the biologists stated.

"Denying the crisis, simply accepting it and doing nothing, or even embracing it for the ostensible benefit of humanity, are not appropriate options, and pave the way for the Earth to continue on its sad trajectory towards a sixth mass extinction."

'Humans are to blame for sixth mass extinction event and we will suffer'

Dr Cara Augustenborg

This latest study confirms what scientists have been warning us about for many years, that the Earth is currently experiencing its sixth mass extinction event, meaning a widespread and rapid loss in the number of species on the planet. 

In a mass extinction, at least three-quarters of all species cease to exist within about 3m years, but at our current rate of species loss, we could lose that number within a few centuries. 

The difference between this mass extinction event and the previous five is, firstly, humans weren’t around to experience any previous mass extinctions.

Secondly, this extinction event is largely due to our exploitation of the planet, including our actions to alter the climate, destroy habitats, pollute the environment and industrialise agriculture. 

This is the asteroid of our own creation, and unlike the asteroid that ended the dinosaurs, we won’t have the luxury of burrowing underground to ride this one out in the same way that a handful of species did to survive 65m years ago.

It could be argued that this extinction crisis dwarfs the climate crisis because humans are so dependent on other species for our existence. 

We need a wide range of animal and plant species to help produce our food, keep soils fertile and provide us with fresh water. 

Without such species, perhaps we can still “survive”, but we most certainly will not thrive. 

Even the chance of experiencing another pandemic becomes more likely as habitats and natural systems are destroyed.

As worrying as this news is, it has received little attention in the mainstream media and within governments. 

In fact, like a scene from the recently released movie satire of the climate crisis and the apathy towards it, Don’t Look Up, this latest study has been laughed off by some commentators as doomsday thinking. 

While climate change has finally reached the consciousness of the public and decision-makers, without better media coverage of biodiversity and this mass extinction event, we are doomed to repeat the same mistakes once again and likely to only begin to take this issue seriously when it is too late to fix it. 

In fact, this biodiversity crisis makes the solution to climate change — to stop burning stuff — look simple. 

Preventing a mass extinction event, on the other hand, requires a level of global cooperation and system change that our species has yet to be able to master, but it can only start with accurate and honest communication about what lies ahead.

Dr Cara Augustenborg is assistant professor in landscape studies and environmental policy at University College Dublin

More in this section

IE_logo_newsletters

Select your favourite newsletters and get the best of Irish Examiner delivered to your inbox

LOTTO RESULTS

Saturday, May 14, 2022

  • 10
  • 11
  • 18
  • 20
  • 35
  • 47
  • 32

Full Lotto draw results »