The Earth Needs 5 Million Years to Recover From Humans: Report
“Entire branches of Earth’s evolutionary tree were chopped off.”
The Earth’s last major extinction involved an asteroid crashing into the planet, vaporizing large segments of crust, and eradicating 76% of all species.
It took a long time for the planet’s biodiversity to recover from that calamity, and many species never returned.
That was 66 million years ago. But the world is now facing another mass extinction event. This time, the cause is more slow-moving and multifaceted than a rock barreling through space — still, the effects are no less devastating.
The current rate of species extinction is far outpacing the general rate of evolution, according to a new study from researchers at Aarhus University and the University of Gothenburg.
And it appears that extinction rates are accelerating as climate change, pollution, habitat destruction, and poaching push more species closer to oblivion.
The Asian elephant, for example, has only a 33% chance of surviving through the century, according to the researchers.
The team wanted to know what would happen if humans stopped harming the planet within 50 years — could biodiversity recover?
Using advanced modeling programs and existing evolutionary data, they determined that it would take 3 to 5 million years for the planet’s biodiversity to recover from the widespread purge expected over the next 50 years and another 2 million years for biodiversity to return to levels seen prior to human life.
This, of course, is a best case scenario because it assumes that human interference will end in the near future.
One of the reasons for the long expected recovery is because many of the animals being wiped out are large mammals that took millions of years to develop.
“Large mammals, or megafauna, such as giant sloths and sabre-toothed tigers, which became extinct about 10,000 years ago, were highly evolutionarily distinct,” said Aarhus University paleontologist Matt Davis, who led the study, in a press release. “Since they had few close relatives, their extinctions meant that entire branches of Earth’s evolutionary tree were chopped off.”
This report joins a growing body of research describing an existential threat facing the planet’s wildlife. Another report found that humans have already caused the annihilation of 83% of all wild mammals and half of all plants.
While these studies paint a grim picture of a world plundered of everything besides humans, the authors of the latest report say that their research can be flipped on its head and used as a conservation tool.
Rather than speculate about how long it would take for a species like the Asian elephant to once again evolve, why not invest in conservation measures that prevent its extinction in the first place?
As significant environmental changes become more apparent, countries are beginning to escalate their conservation efforts.
Chile, for example, created three massive marine sanctuaries and set aside 10 million acres of national parks earlier in the year. In Pakistan, an effort to plant 10 billion trees to foster wildlife is underway. And Botswana has dramatically reduced poaching of elephants over the past decade through improved policing efforts.