GIESSEN, Germany — Humans are to blame for a sixth mass extinction on Earth that is already underway according to experts. Now, to make matters worse, scientists warn that it could take millions of years to undo the damage being done to the planet.
According to an international team of evolutionary biologists, paleontologists, geologists and modelers, today’s crisis does not compare with the previous mass extinction. Scientists say this manmade mass extinction is caused by habitat destruction, climate change, overexploitation, pollution and invasive species.
The last extinction eradicated about 76% of all species on the planet – including entire animal groups such as the dinosaurs. Previous results indicated that the disappearance of marine biota in the wake of the asteroid strike was “considerably higher” than previously believed. On average, the predicted rate was around 1,000 times more, however, this rate will be drastically overshadowed by future losses.
“Even if our impact on the world’s biota stops today, the extinction rate will likely stay high for an extended period of time,” says lead author Dr. Thomas Neubauer, an ecologist at Justus Liebig University Giessen, Germany, in a statement. Scientists warn that a third of living freshwater species will vanish in the next century.
The humble mollusk is vital for ecosystems, since many birds, fish and other animals rely on them for food. Snails consume fungi and leaf litter, helping with decomposition. They also keep other species in check by eating other mollusks.
The study includes 3,387 fossilized and living types of European snails covering the past 200 million years. The researchers focused on freshwater biota as they are among the world’s most threatened. They estimate rates of extinction and the formation of new species to assess the speed at which they come and go and predict recovery times.
Findings suggest prospects for the planet are dire. Extinction rates remained high for 5 million years after the asteroid impact, and recovery took even longer. It was nearly 12 million years until the balance between species originating and dying out was restored.
The pace at which we are losing animals today is unprecedented – and has not even been reached during major extinctions in the past. Damage being done in the next decades to centuries will take millions of years to undo.
“Losing species entails changes in species communities and, in the long run, this affects entire ecosystems. We rely on functioning freshwater environments to sustain human health, nutrition and fresh water supply,” says Dr. Neubauer. He adds that biodiversity decline “outcompetes that at the end-Cretaceous extinction that killed the dinosaurs”.
“Numerous species are threatened with extinction, mostly as a direct or indirect consequence of human impact. Habitat destruction, climate change, overexploitation, pollution and invasive species are among the main causes for Earth’s biota to decline rapidly,” adds Neubauer.
(Credit: Mathias Harzhauser, NHM Vienna.)
The team of researchers state that more than 500 land-based 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’. Those at particular risk included the Sumatran rhino, the Clarion island wren, the Espanola Giant Tortoise and the Harlequin frog.
Another report by conservationists, including the London Zoological Society, warns of a “catastrophic” decline in freshwater fish, with nearly a third threatened by extinction. In UK waters, the sturgeon and the burbot have vanished, salmon are disappearing and the European eel remains critically endangered. Much of the decline is driven by the poor state of rivers, mostly as a result of pollution, dams and sewage.
“Considering the current biodiversity crisis advances much faster than the mass extinction event 66 million years ago, the recovery period may be even longer. Despite our short existence on Earth, we have assured that the effects of our actions will outlast us by millions of years,” said Dr. Neubauer.
This study is published in Communications Earth & Environment.
SWNS writer Mark Waghorn contributed to this report.