The UN Species Extinction Report: Is It Science, or Something Else?

• Edwin S. Rubenstein
• August 5, 2019
• Forum Papers
• Forum Paper
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The UN Species Extinction Report: Is It Science, or Something Else?

An NPG Forum Paper by Edwin S. Rubenstein

One million plant and animal species are now at risk of extinction, endangering ecosystems that people all over the world need for survival. This stark conclusion is from the most exhaustive report ever published on the decline in biodiversity around the world.

“If we want to leave a world for our children and grandchildren that has not been destroyed by human activity, we need to act now,” said Robert Watson, the British chemist who chaired the study, produced by the UN’s Intergovernmental Panel on Biodiversity and Ecosystem Services (IPBES). “If we do not act now, many of the million threatened species will become as extinct as the dodo on this tie,” Watson said, pointing to the image of the late bird on his neckwear.

The E-word is always an attention grabber, often overused by environmentalists because it’s so dramatic and final, and everyone knows about the dodo. Most scientists and other people agree that human encroachment on natural habitats poses a threat to plants and the animals that need them to survive. But it’s a long stretch from there to the idea that one million species are actually threatened with extinction.

Indeed, the notion that one million species even exist is hard for most of us laymen to fathom. Eco-professionals themselves are not sure how many there are: estimates range from 3 to 100 million.2 (Different academic communities – e.g., zoologists, botanists, and bacteriologists – use different levels of differentiation to define a species.)

The UN report settles on 8 million as the number of plant and animal species on Earth. (Remarkably, there is no explanation as to exactly how this figure was arrived at.) Seventy-five percent of all species – about 6 million – are insects, and “available evidence” suggests that 10% of insect species – 600,000 – are threatened with extinction.

Implication: more than half of the one million species at-risk are insects.

What does the one million extinctions figure mean? Is it a gross figure, the number of species that are at risk of extinction, or is it a net figure – species threatened by extinction less the number of new species expected to appear over the same period? Evolution is a continuous process of old species yielding to newer “fitter” ones.

Does the UN focus on species obituaries while ignoring their birth announcements?

The system of naming and describing species used today was created by the Swedish scientist Carl Linnaeus in 1758. In the ensuing 253 years 1.25 million species had been described and entered into central databases.5 In 2011 came the “most precise calculation ever offered” on the number of species on Earth: (Drum Roll): 8.7 million (give or take 1.3 million).

Yet the same 2011 study, published by PLoS Biology, says a staggering 86% of all species on land and 91% of those in the seas have yet to be discovered, described, and catalogued. “Many species may vanish before we even know of their existence, of their unique niche and function in ecosystems, and of their potential contribution to improved human well-being,” says lead author Camilo Mora.

It seems that the more we learn about global species, the more we learn things we don’t know…

Continue reading the full Forum paper by clicking here.