Scientists warn: We live "the first days of the sixth mass extinction of the Earth"

Scientists warn: We live

By Yaiza Martínez

"Defaunation of the Anthropocene" scientists are beginning to refer to the era in which we live and which constitutes, according to a study published in 'Science', the beginning of the sixth mass extinction of the Earth. In 2004, a report from the Earth Policy Institute already warned of this danger, caused by human activities. Therefore, our species is the only one that can solve the problem. Will we be able to use our "collective intelligence" in time for this? By Yaiza Martínez.

A study published yesterday by the journal Science, within a special issue entitled Disappearing fauna -which talks about the dangers of the massive reduction of species- warns that, although the current biodiversity of the planet is the greatest in the history of the Earth, it may be reaching a turning point.

And not precisely for the better, since the degree of loss and deterioration of the terrestrial fauna is such that we could be living "the first days of the sixth mass extinction of the planet," says the research.

In general, "mass extinction" is considered to be the period in which a very large number of species disappear. The best known mass extinction of the five that our planet has suffered took place 65 million years ago, and caused the disappearance of the dinosaurs.

The difference between those extinctions and the one that, according to scientists, is occurring now, is that we are causing this by humans. Therefore, the main author of this article by Science, Rodolfo Dirzo, professor of biology at Stanford University (USA), has baptized it as "defaunation of the Anthropocene".

The first term is a simile with the term "deforestation". The second is a term proposed by some scientists to replace the Holocene, the current Quaternary period in terrestrial history, due to the significant global impact of human activities on terrestrial ecosystems.

Data presented

  • - Since 1500, more than 320 land vertebrates have become extinct. The remaining species populations show an average decrease of 25%.
  • - The situation is equally serious for the life of invertebrates: of the 67% of the monitored invertebrates, a population decrease of 45% has been registered.
  • - Large animals (described as “megafauna”): elephants, rhinos, polar bears and countless other species, face the highest rate of decline, a trend that coincides with previous extinction events. Although these species represent a relatively low percentage of animals at risk, their loss could shake the stability of other species and, in some cases, even human health.
  • For example, experiments carried out in Kenya on the loss of megafauna have revealed that as larger species disappear, rodents increase and, with them, the abundance of ectoparasites carrying diseases that can affect us.
  • - The human population has doubled in the last 35 years. In the same period, the number of invertebrate animals - such as beetles, butterflies, spiders and worms - has been reduced by 45%.
  • - 41% of amphibians are threatened.
  • - 17% of bird species are in danger.

An extinction announced a decade ago

A decade ago, in 2004, it was already alerted that the Earth was experiencing the sixth great mass extinction in its history, the first caused by one of the species that inhabit it; and that the disappearance of species is the most severe in the last 50 million years.

It was in a report prepared by the Earth Policy Institute, an American institution dedicated to promoting sustainable development, chaired by Lester Brown.

At that time, it was warned that our activities cause thousands of species to disappear from our planet every year, from small microorganisms to huge mammals, without many of them even being aware of their existence.

It was also pointed out that the level of extinction reached is between 1,000 and 10,000 times faster than that of the last 60 million years, during which the growth of new species has been faster than the disappearance of other forms of life, a process that has been reversed.

This other report finally pointed out that, thanks to climate change - also caused by human activities - 15% of animal species and 37% of plant species could disappear by 2050.

In 2008, another work by biologists from the University of California at Santa Barbara also pointed out that the Earth is suffering its sixth mass extinction of plants and animals, with about 50% of species disappearing.

Two other studies in 'Science'

The Sinc platform also reports on the content of two other articles that appear in the special Science.

On the one hand, he talks about the work carried out by experts from the University of California and the project Health and Ecosystems: Association Analysis (HEAL) on the social conflicts that would result from the current decline in wildlife.

According to the authors, hunting and fishing involves 400,000 million dollars (about 300,000 million euros a year) and is the livelihood of 15% of the world's population. Therefore, the loss of these resources has caused working conditions to become tougher, hours are extended and wages are reduced through the trafficking of adults and children. In Africa and Asia, for example, the loss of game and fish has hardened working conditions and promoted child exploitation.

The third research published by Science It has been led by Philip Seddon, a researcher at the University of Otago (New Zealand), and it has valued human efforts to reintroduce animals into wild environments and recolonize areas where they had already disappeared.

For the scientist, places where people appreciate their natural heritage the most, such as New Zealand, tend to conserve biodiversity better. "If reintroductions take place in the right habitat, even in human-dominated areas, not only can the species be restored, but human connections to the natural world can also be restored," he adds.

Future cloning techniques that could recover extinct species have also been considered in the work. "This is a very real option that raises many questions about the choice of candidates that could be recovered or whether the ability to 'resurrect' individuals would detract from the global concern about the disappearance of species," says Seddon, of new according to Sync.

The need to apply collective intelligence

When we developed agriculture, 11,000 years ago, in the whole world there were only six million people; But population growth has now led to the decline of the planet's forest cover by 16 million hectares, particularly in forest forests, where the level of biological diversity is highest. The most species-rich swamps were also cut in half during the 20th century.

Those are some of the consequences of human overpopulation, but also of poor resource management. In this sense, the greatest current threat to life comes from the degradation of habitats, a situation that affects 90% of the most sensitive species on Earth.

Among the solutions, Rodolfo Dirzo proposes, in a statement from Stanford University, to immediately reduce the rates of transformation of habitats and overexploitation, with approaches adapted to individual regions and situations.

Justin Brashares, lead author of the second study mentioned and a researcher at the University of California, has pointed out to Sync that, to deal with the problem, it would be necessary to design measures that "recognize the affected areas, identify the interested parties and work with local governments through international agreements."

The authors of the three studies seem to agree, therefore (Philip Seddon spoke that in those "places where the natural heritage is most appreciated, biodiversity is usually better conserved"), in the importance of local work to, joining pieces, obtain a large-scale result.

This conception of solutions is essential, since it indicates that it would partly be in the hands of everyone - citizens and political leaders of towns, cities or regions, in collaboration with state governments - to devise, promote, support and collaborate in initiatives that modify this worrying panorama . As proposed by the forest management expert and director of the company Mirlo Positive Nature, Yeray Martínez, to Trends21 in 2013, "collective intelligence could save the environment." We will see if the excessive ambition and its associated stupidity do not prevent it.


Video: Stanford researcher warns sixth mass extinction is here (May 2021).