When Mass Extinctions Begin to Accelerate

What’s happening is a tragedy, but not a surprise

Photo by Jean Wimmerlin on Unsplash

It’s been 5 years since a study co-authored by PIC patron Dr. Paul Ehrlich revealed that, even by conservative estimates of human activities, the Earth has been undergoing exceptionally rapid biodiversity loss, with species disappearing up to 100 times faster than the normal rate.

But a study released earlier this month, also co-authored by Ehrlich, is even more alarming. It turns out the extinction rate among terrestrial vertebrate species is significantly higher than prior estimates, and the critical window for preventing mass losses will close much sooner than we thought — likely in 10 to 15 years.

If nothing changes, about 500 more terrestrial vertebrate species are likely to go extinct over the next two decades, bringing total losses equivalent to those that would have taken place naturally over 16,000 years.


Dr. Ehrlich says that the overall findings are almost certainly a gross underestimate of the true scope of the extinction problem because the analysis did not take plants, aquatic vertebrates such as fish, or any kind of invertebrate species into account.

As a matter of fact, it included only about 5 percent of terrestrial vertebrates for which scientists have population data.

Additionally, we should consider that:

  • Continued loss at the current rate means the Earth stands to lose vast ecosystems along with the necessities they provide, including fresh water, pollination, and pest and disease control.
  • The loss of some species will likely trigger a domino effect that sends others into a downward spiral, ultimately threatening entire ecosystems. The scientists conclude that conservationists should therefore consider all species with populations under 5,000 individuals to be in danger of extinction.
  • Habitat loss and wildlife trade are currently responsible for the bulk of the problem, whereas climate change has yet to unleash “the full tsunami” of its impacts.


While the authors of the study are calling for an immediate end to illegal wildlife trade and deforestation, as well as complete reform of the legal wildlife trade, Dr. Ehrlich notes that the most fundamental problem is “reducing the scale of the human enterprise, especially its consumptive demands on the biosphere.”

Making massive, significant change on this scale will require electing leaders who prioritize the environment, redistributing resources and, most controversial of all, slowing and eventually reversing human population growth. Dr. Ehrlich is helping to launch a new global initiative called Stop Extinction that aims to provide a framework for creating new international agreements and tools for educating and activating the public about the unfolding extinction crisis. We at PIC hope it creates a catalyst for a conversation about the ongoing population crisis and spurs much-needed action by every country to achieve a sustainable population, because universal, affordable contraception for all, along with the promotion of small families, are essential steps to bringing the human population to a sustainable level.

The recent study shows that it’s not enough to slow human population growth — we must reverse it. Unfortunately, the human population is still growing by some 80 million people annually, in a world already being depleted by a population of 7.8 billion.

As ecologist Thomas Lovejoy observes in the New York Times article, the fact that so few people are aware of this impending crisis is a cause of the crisis itself. But, as we reported in our news release earlier this month on Sir David Attenborough, those who make the connection between population growth and the global ecological crisis still come under attack.

It’s long past time to break the taboo on speaking about population growth. The window is closing on our ability to save a significant part of our planet’s biodiversity from extinction so we all must do what we can now to raise awareness of the connection between our continued growth and the environmental crisis.

Please join and engage with us on FacebookTwitter or LinkedIn, where we do our best to educate and inform others about the consequences of overpopulation. We’d be glad to have you join us.


Madeline Weld, Ph.D.
President, Population Institute Canada
Tel: (613) 833-3668
Email: [email protected]