Grizzlies were already extinct in California three decades before the Legislature named it the state animal in 1953.
Ceballos said that, ever since he was a child, he struggled to understand why certain animals went extinct.
“We are not likely to lose the honeybee as a species, but we’re already losing it in lots of places were it’s very important say for pollinating your almond orchards,” said Ehrlich.
“The number of species that have gone extinct in the last century would have taken… between 800 and 10,000 years to disappear”, the study reported.
Based on those figures, the extinction rate since 1900 has been eight to 100 times higher than the expected background rate, the researchers said.
Even when the researchers only included species that were confirmed extinct, 198 species, the die-off was 22 times the background rate. His 1981 book, “Extinction: The Causes and Consequences of the Disappearance of Species“, began a string of doomsday concerns caused by coevolution, racial, gender and economic justice riots, and nuclear winter.
About 41 per cent of all amphibian species and 26 per cent of all mammals are threatened with extinction, if worldwide Union for Conservation of Nature is to be believed. We’re also cutting down forests, introducing invasive species and releasing poisons into fragile ecosystems.
You’ve heard it before, but now there’s more proof: A sixth great mass extinction is underway, and we’re running out of time to stop it.
According to studies carried out, the last of five mass extinctions actually happened some 66 million years ago when dinosaurs were exterminated from the face of the earth. [Wipe Out: History’s Most Mysterious Extinctions].
“[The study] shows without any significant doubt that we are now entering the sixth great mass extinction event,” said Paul Ehrlich, the Bing Professor of Population Studies in biology and a senior fellow at the Stanford Woods Institute for the Environment. And it can take millions of years for life to recover and repopulate the Earth, he said.
Fully 396 species have gone extinct in 100 years. But some vertebrate populations have so few individuals left that they can’t efficiently play their role in the ecosystem, Ceballos said.
Writing in the journal Science Advances, the researchers concluded: “Our analysis emphasises that our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years”.
On why people should be anxious about the rate of extinctions, he said: “People say that’s really sad, but why does it affect me?”
But this latest effort is by far the most conservative: a study aimed at debunking any possible rebuttal that its findings are “alarmist”.
According to specialists, Earth is seemingly getting into its sixth mass extinction interval.
The research also indicates that humans are to blame for these worrying rates of extinctions.
Biodiversity provides critical functions, including the air in the atmosphere and purifying drinking water – life as we know it depends on having high levels of species diversity, scientists say.