Experts warn that a Sixth Mass Extinction is potentially underway, with human activities threatening species extinction
Earth has undergone mass biodiversity extinctions five times before.
Now, scientists find that a Sixth Mass Extinction – caused by human activities, creating climate change and endangering species – may be happening right now.
Published in Biological Reviews, biologists from the University of Hawai‘i at Mānoa and the Muséum National d’Histoire Naturelle in Paris conducted a comprehensive assessment of evidence of this ongoing extinction event.
Finding evidence for a major biodiversity crisis
By using estimates and data taken on land snails and slugs, the researchers estimated that the Earth could already have already lost between 7.5 and 13% of the two million known species on Earth, since the year 1500. This percentage accounts for around 150,000 to 260,000 species.
However, this situation is not applicable everywhere. Although marine species face significant threats, there is no evidence that the crisis is affecting the oceans to the same extent as the land. For instance, on land, island species are much more affected than continental species, such as those of the Hawaiian Islands, compared with those on mainland America. As well as this, the rate of extinction of plants seems lower than that of terrestrial animals.
Robert Cowie, lead author of the study and research professor said: “Drastically increased rates of species extinctions and declining abundances of many animal and plant populations are well documented, yet some deny that these phenomena amount to mass extinction.
“This denial is based on a biased view of the crisis which focuses on mammals and birds and ignores invertebrates, which of course constitute the great majority of biodiversity. Including invertebrates was key to confirming that we are indeed witnessing the onset of the Sixth Mass Extinction in Earth’s history.”
“It is clear that political will is lacking”
The study explains that many people deny the beginning of the Sixth Extinction, along with science denial becoming more debated in modern society on numerous issues, such as climate change. Additionally, others accept it as a new and natural evolutionary trajectory, suggesting humans are just another species playing their ‘natural role’ in Earth’s history.
They found that many people even consider that biodiversity should be manipulated solely for the benefit of humanity – to which the researchers tried to figure out who this benefit is defined by.
Can we stop the Sixth Mass Extinction?
To divert the crisis, numerous conservation strategies have been successful for certain animals, however, these initiatives cannot cover all species, and they cannot reverse the overall trend of species extinction. However, it is still essential to continue conservation efforts, to continue to improve human care for nature, and to document biodiversity before it becomes extinct.
Professor Cowie added: “Humans are the only species capable of manipulating the biosphere on a large scale. We are not just another species evolving in the face of external influences. In contrast, we are the only species that has conscious choice regarding our future and that of Earth’s biodiversity.
“Despite the rhetoric about the gravity of the crisis, and although remedial solutions exist and are brought to the attention of decision-makers, it is clear that political will is lacking.
“Denying the crisis, accepting it without reacting, or even encouraging it constitutes an abrogation of humanity’s common responsibility and paves the way for Earth to continue on its sad trajectory towards a Sixth Mass Extinction.”