Are 30 thousand species going extinct every year?

Summary: The warnings become increasingly dire and shrill as we approach November’s United Nations Climate Change Conference in Paris. One theme warns about the increasing rate of extinctions, described with astonishing numbers — and projected to add humanity to the endangered species list. As usual, these claims distract attention from serious and imminent threats, such as our dying oceans. Let’s look beyond the hysteria to the science.

 

Contents

1. Our certain doom from the great extinction.
2. How many species are there?
3. How many species have gone extinct?
4. Should we fear forecasts of mass extinction?
5. Conclusion.
6. For More Information.
7. For a useful perspective on these matters.

 

(1)  Our certain doom, chapter XXI: the great extinction

Exaggeration is the primary tool of activists in the publicity campaign to force public policy changes to fight climate change. “Anything goes” became their watchword once they broke free from the peer-reviewed literature.

It starts with science at the website Endangered Species International — “More than 16,000 species are threatened to become extinct in the near future.” “Of the 44,838 species assessed worldwide using the IUCN Red List criteria, 905 are extinct {was 784 in 2006} and 16,928 are listed as threatened to be extinct.”

Next politics goes wild: The Convention on Biological Diversity went into force in December 1993. Among its best known results are these words by Executive Secretary Ahmed Djoghlaf on 21 May 2007 — about extinctions happening now (not just threatened for the future).

“Every hour, three species disappear. Every day, up to 150 species are lost. Every year, between 18,000 and 55,000 species become extinct.  The cause: human activities. … Climate change is one of the major driving forces behind the unprecedented loss of biodiversity. “

This has frequently been debunked. But even after 8 years of rebuttals to this and similar exaggerations, Real News Network repeats this claim in Climate Change: Have We Reached the Point of No Return? (Climate change zombie myths live on the Left, much as Zombie Economics does on the Right.) The RNN story has the typical climate activists’ mix of unbalanced facts, assertions far outside the climate science consensus (and the IPCC), plus exaggerations. They used the poster at the top if this post as their headline graphic.

(2)  How many species are there?

Before estimating how many species have gone extinct — are going extinct, and how many will go extinct — we need to know how many there are. There are millions (estimates vary widely), many of which are genetically close to others in their genus or live in tiny geographic ranges. Island species are especially vulnerable.

See this summary from “The biodiversity of species and their rates of extinction, distribution, and protection” by S. L. Pimm et al, Science, 30 May 2014. Ungated copy.

Interestingly, several targets explicitly mention “known species” — a strong, if implicit statement of incomplete knowledge. So how many eukaryote species are there? For land plants, there are 298,900 accepted species’ names, 477,601 synonyms, and 263,925 names unresolved. Because the accepted names among those resolved is 38%, it seems reasonable to predict that the same proportion of unresolved names will eventually be accepted. This yields another ~100,000 species for a total estimate of 400,000 species.

Models predict 15% more to be discovered, so the total number of species of land plants should be >450,000 species, many more than are conventionally assumed to exist.

For animals, recent overviews attest to the question’s difficulty. About 1.9 million species are described; the great majority are not. Costello et al. estimate 5 ± 3 million species, Mora et al. 8.7 ± 1.3 million, and Chapman 11 million. Raven and Yeates estimate 5 to 6 million species of insects alone, whereas Scheffers et al. think uncertainties in insect and fungi numbers make a plausible range impossible.

Estimates for marine species include 2.2 ± 0.18 million, and Appeltans et al. estimate 0.7 to 1.0 million species, with 226,000 described and another 70,000 in collections awaiting description.

(3) How many species have gone extinct?

“Most extinctions have occurred on oceanic islands or in restricted freshwater locations, with very few occurring on Earth’s continents or in the oceans.”
— John C. Briggs (Prof Marine Science, U South FL) in Science.

All counts of extinct species in modern times are disproportionate to the wild claims by activists. Even the BBC asks “Biodiversity loss: How accurate are the numbers?” (2012).

“Current estimates of the number of species can vary from, let’s say, two million species to over 30 or even 100 million species,” says Dr Braulio Dias, executive secretary of the Convention on Biological Diversity. “So we don’t have a good estimate to an order of magnitude of precision,” he says.

But if it’s really true that up to 150 species are being lost every day, shouldn’t we expect to be able to name more than 801 extinct species in 512 years?

That is the right question, one of two questions about extinctions that activists don’t want you to ask. For an answer turn to “Accelerated modern human–induced species losses: Entering the sixth mass extinction” by Gerardo Ceballos and Paul R. Ehrlich {!} et al, Science Advances, 19 June 2015 — With doomster Paul Ehrlich (with his history of wrong predictions) as co-author, they can’t be accused of minimizing the problem when saying only 477 vertebrates have gone extinct since 1900. Click to enlarge.

The other question too seldom asked is about the contribution of climate change to past and current extinctions. It’s small (so far) compared to the massive damage from hunting/fishing, introduction of new species (e.g. rats, goats, Burmese pythons), pollution, and habitat loss. These create serious and ongoing threats to the biosphere, but too often are ignored among the predictions of doom from climate change.

(4) Should we fear these forecasts of mass extinction?

Probably not, for several reasons. First, the method of extrapolation used to produce those large numbers relies on experience with islands — which might not scale up to continents. The key paper discovering this was “Species–area relationships always overestimate extinction rates from habitat loss” by Fangliang He & Stephen P. Hubbell, Nature, 19 May 2011 — Abstract (red emphasis added) …

Extinction from habitat loss is the signature conservation problem of the twenty-first century. Despite its importance, estimating extinction rates is still highly uncertain because no proven direct methods or reliable data exist for verifying extinctions.

The most widely used indirect method is to estimate extinction rates by reversing the species–area accumulation curve, extrapolating backwards to smaller areas to calculate expected species loss. Estimates of extinction rates based on this method are almost always much higher than those actually observed. This discrepancy gave rise to the concept of an ‘extinction debt’, referring to species ‘committed to extinction’ owing to habitat loss and reduced population size but not yet extinct during a non-equilibrium period.

Here we show that the extinction debt as currently defined is largely a sampling artefact due to an unrecognized difference between the underlying sampling problems when constructing a species–area relationship (SAR) and when extrapolating species extinction from habitat loss. The key mathematical result is that the area required to remove the last individual of a species (extinction) is larger, almost always much larger, than the sample area needed to encounter the first individual of a species, irrespective of species distribution and spatial scale. We illustrate these results with data from a global network of large, mapped forest plots and ranges of passerine bird species in the continental USA; and we show that overestimation can be greater than 160%.

Although we conclude that extinctions caused by habitat loss require greater loss of habitat than previously thought, our results must not lead to complacency about extinction due to habitat loss, which is a real and growing threat.

There are other factors debunking those estimates that thousands of species are going extinct every years. For a non-technical summary of these and actual good news about extinction rates (i.e. that the news is bad but not catastrophic) see “Rethinking Extinction” by Stewart Brand at Aeon — “The idea that we are edging up to a mass extinction is not just wrong – it’s a recipe for panic and paralysis.” Brand edited the Whole Earth Catalog (1968-74); now he is president of the Long Now Foundation and co-founder of the Revive and Restore project in San Francisco. Also see his articles about de-extinction.

(5) Conclusion

These exaggerations are typical of climate activists, making their massive project one of the most incompetent publicity campaign ever. As the years roll by people will wonder about those forecasts that tens of thousands of species are going extinct every year — while only a few score animals are added to the extinct list.

Not only might this inconvenient truth wash away the credibility of the climate change campaign, but it might damage that of science as well. Also, decades of false warnings about certain disaster appear to have made the public skeptical or even disinterested in the doom du jour, as in the Boy Who Cried Wolf. Remember the ending: eventually the wolf came, but nobody listened.

And what’s the result of this risky campaign? Climate change ranks at the bottom of most surveys of what Americans’ see as our greatest challenges. (CEOs, too.)

We can only guess if a more truthful campaign would have succeeded. If only activists had tried. It’s a problem seen throughout American politics. A closer grasp of the truth might be a necessary start for any reform program in America.

(6)  For More Information

More samples from the large body of research about this topic…

• “Extinction risk from climate change” by Chris D. Thomas et al, Nature, 8 January 2004 — Ungated copy here.
• “8.7 Million: A New Estimate for All the Complex Species on Earth” by Daniel Strain, Science, 26 August 2011. Ungated copy here.
• “Can We Name Earth’s Species Before They Go Extinct?” by Mark J. Costello et al, Science, 25 January 2013. Ungated copy here.
• For the most accurate list of extinct and endangered species, see the IUCN Red List of extinctions. Wikipedia posts this in more easily viewed form.

Please like us on Facebook, follow us on Twitter, and post your comments — because we value your participation. For more information see The keys to understanding climate change and My posts about climate change. Also see these…

• About models, increasingly often the lens through which we see the world.
• We must rely on forecasts by computer models. Are they reliable?
• Will we see the end of snow? More importantly, when will we learn to see the world clearly?
• Do models accurately predict climate change?
• Six headlines from 2009 telling us important news about 2015’s climate.

(7)  For a useful perspective on these matters

I recommend reading “Contrasting Good & Bad Science: Disease, Climate Change & the Case of the Golden Toad“, adapted from the chapter “Beating Dead Frogs with CO2” from Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism by Jim Steele (2013). See his background here, and this excerpt…

To insure the public does not become complacent as the 16-year hiatus in rising global temperatures continues, the media is spammed with untested models claiming rising CO₂ is and will spread death and destruction via food shortages and disease.

As MIT’s world-renowned oceanographer Carl Wunsch warned “Convenient assumptions should not be turned prematurely into “facts,” nor uncertainties and ambiguities suppressed … Anyone can write a model: the challenge is to demonstrate its accuracy and precision … Otherwise, the scientific debate is controlled by the most articulate, colorful, or adamant players.”

As presented here before, the extinction of the Golden Toad illustrates the great abyss that separates the rigor of good medical science from the opportunistic models trumpeted by a few articulate and adamant climate scientists. The lack of substance in climate propaganda is revealed when we compare the details that led epidemiologists to blame a fungus and modern transportation for the Golden Toad’s extinction.