Sixth Mass Extinction Caused by Human Activities, Warn Scientists
The history of the Earth is overshadowed by five mass extinctions that destroyed most species. The last famous extinction occurred 66 million years ago, when the asteroid destroyed dinosaurs. However, now scientists warn of the sixth mass extinction caused by human activities. A study published in pnas shows that the disappearance of related groups of animals occurs 35% faster than usual.
Gerardo Sebalos, senior researcher at the Institute of Ecology of the National Autonomous University of Mexico, suggests that this extinction can radically change the biosphere, making it unsuitable for human life. While the “large five” mass extinctions had different reasons, understanding of past events can help in studying the current disaster.
Radiometric dating and other methods shed light on the history of mass extinctions. For example, the discovery of the “Irridia anomaly” – a layer rich in iridium, rare on Earth, but ordinary in meteorites, indicated an asteroid that caused mass extinction at the end of the Cretaceous period.
In the history of the Earth there were other disasters. For example, the “great dying”, which occurred 252 million years ago, was caused by global warming after the eruptions of volcanoes. Or the mass extinction at the end of the Triassic period 201 million years ago, associated with the breakdown of the Pangea supercontinent and the formation of the central part of the Atlantic Ocean.
However, the current, sixth mass extinction is unique in that it is caused by human activity. Since people left their mark around the world, many species have disappeared, including the Dodo, the Tasmansk Tiger, Bajei, and the Western Black Losorog. The reasons for these extinctions are diverse: a change in land use, loss of habitat, deforestation, intensive agriculture, and