GIESSEN, Germany — Humans are responsible for a sixth mass extinction on Earth that is already underway according to experts. Now, to make matters worse, scientists are warning that it could take millions of years to undo the damage done to the planet.
According to an international team of evolutionary biologists, paleontologists, geologists and modellers, the current crisis is not comparable to the previous mass extinction. Scientists say this man-made mass extinction is caused by habitat destruction, climate change, overexploitation, pollution and invasive species.
The last extinction eradicated around 76% of all species on the planet, including entire groups of animals like the dinosaurs. Previous results indicated that the loss of marine biota following the asteroid impact was “significantly higher” than previously thought. On average, the expected rate was about 1,000 times higher, but this rate will be drastically eclipsed by future losses.
“Even if our impact on global biota stops today, the extinction rate will likely remain high for an extended period,” says lead author Dr. Thomas Neubauer, ecologist at Justus Liebig University Giessen. , in Germany, in a press release. Scientists warn that a third of living freshwater species will disappear in the next century.
The humble mollusk is vital to ecosystems, as many birds, fish and other animals depend on it for food. Snails eat mushrooms and dead leaves, helping with decomposition. They also control other species by eating other molluscs.
The study includes 3,387 fossilized and living types of European snails spanning the last 200 million years. The researchers focused on freshwater biota because they are among the most threatened in the world. They estimate rates of extinction and the formation of new species to gauge the rate at which they come and go and predict recovery times.
The results suggest that the outlook for the planet is dire. Extinction rates remained high for 5 million years after the asteroid impact, and recovery took even longer. It took nearly 12 million years for the balance between the origin and disappearance of species to be restored.
The rate at which we are losing animals today is unprecedented – and hasn’t even been reached during major extinctions in the past. The damage done over the next few decades, if not centuries, will take millions of years to repair.
“The loss of species leads to changes in species communities and, in the long term, this affects entire ecosystems. We rely on functioning freshwater environments to support human health, nutrition and freshwater supply,” says Dr. Neubauer. He adds that the decline in biodiversity “surpasses that of the late Cretaceous extinction that killed the dinosaurs.”
“Many species are threatened with extinction, mainly as a direct or indirect result of human impact. Habitat destruction, climate change, overexploitation, pollution and invasive species are among the main causes of the rapid decline of terrestrial biota,” adds Neubauer.
The research team says that more than 500 terrestrial animal species will be on the brink of extinction within the next 2 decades. They called for immediate global conservation actions to prevent a “catastrophic ecosystem collapse”. Species particularly at risk included the Sumatran rhinoceros, Clarion Island wren, Espanola giant tortoise and Harlequin frog.
Another report from conservationists, including the London Zoological Society, warns of a “catastrophic” decline in freshwater fish, nearly a third of which are threatened with extinction. In British waters, sturgeon and burbot have disappeared, salmon are disappearing and European eels remain critically endangered. Much of the decline is due to the poor state of the rivers, mainly due to pollution, dams and sewage.
“Since the current biodiversity crisis is progressing much faster than the mass extinction event of 66 million years ago, the recovery period could be even longer. Despite our short existence on Earth, we have assured that the effects of our actions will survive us for millions of years,” Dr. Neubauer said.
This study is published in Earth & Environment Communications.
SWNS writer Mark Waghorn contributed to this report.