Patrick Moore's Biodiversity Denial Debunked
Chapter 5 Fact-check: Moore calls the scientific estimate that one million species face extinction "shameless fakery." Here's the taxonomy he doesn't understand.
Published October 21, 2023 · Updated August 24, 2026
In Chapter 5, Moore finds fault with the work of biological taxonomists who estimate that one million species around the world are under threat of extinction due to climate change and other related environmental issues. He also finds fault with the current estimates made by taxonomists who cite the research that estimates there are 8.7 million species in the world today.
In this chapter, Moore seethes against the estimates made by biologists, and against the global infrastructure of knowledge about threats to species. Moore stumbles hard, spilling mistakes, errors and falsehoods left and right.
Throughout the chapter, Moore keeps insisting in various long-winded ways that science can’t make estimations. He claims of the un-identified species that scientists believe exist, “we do not have any clue as to whether the 6.69 million species actually exist…I call this fakery at the most shameless possible level. These species are imperceptible and have no identifications, and yet they are able to make the most accurate estimate ever?”
I reached out to Dr. Andy Purvis, the lead author of the report that Moore focuses on in this chapter. Purvis helped explain the errors made by Moore.
My Life with Taxonomy is a Testimony to Moore’s Falsehoods
Patrick Moore has spent much of his life in stuffy offices, his back turned to the natural world. I have been lucky to have spent much of my adult life in the outdoors. I have seen and identified 1,300 bird species, 350 fish species, 200 butterfly species, 150 reptile and amphibian species, 50 dragonfly and damselfly species, and countless mammals, moths, trees, shrubs, wildflowers, beetles, fungi, orchids and more. Learning the names of species and identifying them as an amateur in the wild is one thing, but formally describing them is another.
I photographed this unidentified fly in the San José del Cabo Estuary.
Luckily, in this life, I have had the pleasure of meeting, interviewing and working with dozens of biologists and even biological taxonomists. I have helped ornithologists tag endangered birds, I have collaborated with coral biologists and marine biologists. I have hiked with botanists on surveys. Having been able to peer into this world - the world of species taxonomy - gives me a good smell test when reading Patrick Moore’s self-published book. By knowing the incredible amount of education, resilience, expertise and peer-review support it takes to be a taxonomic specialist, I know how full of bologna Patrick Moore is in this book.
Biological taxonomists are scientists who specialize in the classification, identification, and naming of living organisms. Their work is crucial for organizing the vast diversity of life on Earth into a systematic and hierarchical framework.
Taxonomists are usually very specialized, focusing on very specific taxa. In their profession, they examine the morphological, anatomical, and genetic characteristics of organisms to determine their unique features. They classify these organisms into hierarchical categories based on their evolutionary relationships. They assign them scientific names following a standardized system of nomenclature, usually governed by the International Code of Nomenclature for algae, fungi, and plants or the International Code of Zoological Nomenclature. They often use genetic information, such as DNA or RNA, to understand evolutionary relationships between organisms. Molecular techniques, such as DNA sequencing, contribute to more accurate classifications. Many taxonomists conduct fieldwork to observe organisms in their natural habitats.
Despite being very specialized in the taxa they study, taxonomists often collaborate with researchers from various fields such as ecology, genetics, and environmental science. This interdisciplinary approach helps us to build a comprehensive understanding of living organisms.
Let’s Break Down what we Know about Species
The identification of a species in science involves a comprehensive process usually initiated by a taxonomist. Initially, researchers may discover a new organism through fieldwork, specimen collection, or molecular studies. The taxonomist then carefully examines morphological, anatomical, and genetic characteristics of the organism, comparing them with known species. This analysis includes detailed observations of features such as size, color, shape, and internal structures. If the new organism exhibits distinct differences and meets specific criteria, the taxonomist formally describes and names it according to established nomenclature rules. The scientific community may peer-review and validate the identification before the new species is officially recognized and documented in scientific literature, contributing to our understanding of biodiversity.
This Black-capped Tanager, which I photographed in Magdalena Department, Colombia, is one of 11,188 described birds.
The organization that provides the best data on the current numbers of recognized species is the IUCN. The IUCN, or the International Union for Conservation of Nature, is a global organization dedicated to the conservation and sustainable use of natural resources. It is the world's largest and most diverse environmental network, bringing together governments, NGOs, scientists, and experts to address conservation challenges. The IUCN was established in 1948 and is headquartered in Gland, Switzerland.
According to the IUCN, 2,161,755 species have been described as of November 2022.
Number of Described Species According to the IUCN
Moore is Dead Wrong about Estimation in Science
Estimation is an integral part of science, and in the field of biology, particularly in species taxonomy, it plays a crucial role in understanding and quantifying the diversity of life on Earth.
In taxonomy, estimation is essential. The Earth hosts an immense variety of species, but identifying and cataloging each one is a monumental task. Taxonomists use methods such as field surveys and sampling, to identify and classify species within a given area.
Due to practical limitations and the vastness of unexplored regions, taxonomists cannot identify every species on Earth - imagine, for example, how little we know about the creatures that inhabit the Mariana Trench. Estimation allows them to extrapolate from sampled data to estimate the total diversity within a broader ecosystem or even globally.
A Kankuamo marquezi spider is one of 110,615 described arachnids. This species, the only one in its genus, is known for sword-shaped hairs that sting predators, unlike other tarantulas, which can throw their hair. Many of the species I saw in Colombia don't even have common names, as they have only recently been described — a reminder that 10,000 to 15,000 new species are being described every year. See my entire spider life list.
Taxonomists often use sampling techniques to study a representative subset of a population or ecosystem. This could involve collecting specimens from specific habitats, using traps, or employing DNA analysis.
The data obtained from these samples are then extrapolated to estimate the total number of species in the larger population. Statistical methods help account for uncertainties and variability in the sampled data.
DNA barcoding involves analyzing specific regions of an organism's DNA to identify and classify species. This technique is particularly useful when traditional morphological identification is challenging. Estimation is inherent in the use of DNA barcoding, as taxonomists may not analyze the entire genome of every specimen. Instead, they focus on specific genetic markers to make broader inferences about relatedness and diversity.
Some species are cryptic, meaning they have subtle morphological differences that make identification challenging. Estimation becomes crucial in recognizing and understanding the hidden diversity within these cryptic species.
Molecular tools, combined with traditional taxonomy, help reveal the presence of cryptic species and estimate their abundance in ecosystems.
Estimating the total number of species globally is a monumental challenge. Taxonomists use a combination of regional studies, extrapolation methods, and modeling to arrive at estimates of global species diversity.
These global estimates are vital for conservation efforts, as they help prioritize areas of high biodiversity and guide strategies to protect ecosystems with unique and threatened species.
Moore Screws up Big-time on the Estimate of Global Species
In this chapter, Moore repeatedly tries to break down the legitimacy of the current estimate that there are 8.7 million species on Earth. He makes it sound as though that number were made up by the organization which presented the data to congress; he plays tricks with his words that makes it sound as though the estimate was some quickly made-up number by an unqualified partisan.
Nothing could be further from the truth. There have actually been many estimates about the total number of species on Earth. Most of them range from about 5 million species to 12 million species. However, the most accepted estimate - and therefore the most cited estimate - is 8.7 million species.
This estimate is often attributed to the work of Dr. Camilo Mora and his colleagues, whose study was published in the journal "PLoS Biology" in 2011. The study aimed to provide a comprehensive estimate of the total number of species on Earth, including both described and yet-to-be-discovered species.
Several factors contribute to the high citation and recognition of this study. The study used a novel and comprehensive approach to estimate global species diversity, combining data from various sources, including taxonomic databases, scientific literature, and expert opinions. This interdisciplinary approach helped to overcome limitations of individual methods.
Tillandsia confinis, a type of air plant from the family Bromeliaceae. About 650 Tillandsia air plants have been identified, but plants have some of the highest diversity on Earth — 424,335 plants have been identified, according to the IUCN.
The study involved collaboration among researchers from different disciplines and regions, fostering a global perspective on biodiversity. This collaborative effort adds credibility and influence to the findings.
The study underwent rigorous peer review and scrutiny, meeting the standards of scientific excellence. Its publication in a reputable journal adds to its credibility and ensures that it has been subjected to expert evaluation.
The study considered various taxonomic groups and ecosystems, providing a more holistic perspective on global biodiversity. This approach is valuable for understanding the interconnectedness of different species and ecosystems.
The exact number of species on Earth remains far from certain, and ongoing research, advances in technology, and exploration of previously inaccessible areas may refine our understanding of global biodiversity over time. Even our understanding of what a species is, and isn’t, is changing over time. But Moore’s misguided attempts to discredit the most cited estimate on biological diversity is baseless, and Moore is unable to surface any credible challenge to it. While he calls the estimate ‘shameless fakery’, his non-scientific rant about politics allows him to sidestep the data.
In this chapter, Moore stepped heavily into the Slothful Induction Fallacy, where despite strong evidence for the authority of the 2011 study, Moore attempts to shift credit for its creation to the panel making a presentation to US congress. Moore is also guilty of The Tu Quoque Fallacy, where instead of providing evidence for his assertions, he spends the chapter trying to discredit the proponents of the data, rather than focusing on the integrity of his own claims.
Moore’s Attack on Global Threats to Species is Misguided Misinformation
Moore’s intention, by going after the 8.7 million species estimate, is ultimately to discredit the claim made by the IPBES that one million species are at risk of extinction. Moore calls these threats to extinction a “scare story…based on unobservable factors that cannot be independently checked by sensible people.”
Instead of providing an argument as to why he believes the estimate about threats to species is a baseless scare story, he pivots in another Tu Quoque Fallacy to simply complaining that his testimony was cancelled and not part of the official record, complaining that the science-based estimators went “uncontested and free to peddle their twaddle.”
In reality, his testimony was cancelled because it was immediately apparent he was an angry partisan with no knowledge of the subject, and not an expert.
One of the themes of Moore’s book is to repeatedly claim that if ‘sensible people’ can’t understand or directly observe something, then it must be false. Most science is complex, and for laymen to understand and synthesize complex scientific estimates, they need to put in the effort. Thankfully, there is a high degree of transparency to the tool used by scientists who estimated the total number of global species threatened with extinction - the IUCN Red List.
The IUCN Red List is widely regarded as an authoritative tool for cataloging threats to species around the world. Its authority stems from its standardized assessment methodology, which provides a consistent framework for evaluating the conservation status of species across different taxa and geographic regions. This methodology ensures that assessments are conducted using rigorous scientific principles and the best available data, including population trends, distribution, habitat loss, and specific threats facing each species.
Transparency and accountability are key factors contributing to the Red List's authority. The assessment process is transparent, with detailed documentation of methodologies and criteria publicly available. This transparency allows for scrutiny and review by the scientific community, enhancing the credibility of the Red List as a trusted source of information on species' extinction risk.
One of the most significant aspects of the Red List's authority is its global scope. Covering a wide range of taxa, including mammals, birds, amphibians, reptiles, fishes, invertebrates, and plants, the Red List enables comprehensive assessments of biodiversity across diverse ecosystems and regions. This breadth of coverage makes it an invaluable tool for understanding global conservation priorities and identifying species most in need of conservation attention.
The report presented to congress was led by Dr. Andy Purvis, who explains that the number of estimated threatened species is based on the percentage of threatened species catalogued in the IUCN Red List. He explains that based on the idea that 10% of insect species, or about 500,000 insects, are threatened with extinction and 25% of all other species, or about 500,000 species are also threatened with extinction, you arrive at the estimate of one million species.
Moore’s Graph on Extinctions is Misleading, and was Debunked by the IUCN
In Chapter 5, Moore shows a graph which shows that the number of species that are going extinct is declining. But the graph he cites was actually created by the low-credibility political group CO2 Coalition, of which he is a prominent director and which advocates the non-scientific position that more CO2 is healthy for the planet. In a well-written debunking of this chapter, Professor Sean Holman reached out to Craig Hilton-Taylor, the head of the International Union for Conservation of Nature’s red list of endangered species.
Hilton-Taylor explains how Moore’s graph was misleading. “Indeed…it’s a reverse image of [Patrick Moore’s] graph.”
Moore makes other mistakes in this chapter. For example, he claims that, “It was not until the extinction of the passenger pigeon in 1914 that the general public became concerned with and supported programs to prevent further extinctions.”
This is simply not true. Concerns about species extinction and conservation efforts existed prior to the extinction of the passenger pigeon. Throughout the 19th and early 20th centuries, there were various movements and organizations advocating for the protection of wildlife and habitats. For example, the establishment of Yellowstone National Park in 1872 marked the beginning of the national park system in the United States, driven by concerns about preserving wilderness and wildlife.
The decline of the American bison, for example, prompted conservation efforts in the late 19th century, leading to the establishment of protected areas and conservation measures to save the species from extinction.
It is more accurate to say that the extinction of the passenger pigeon was a significant moment in the history of conservation, highlighting the devastating impact of human activities on wildlife and ecosystems. However, it would be incorrect to suggest that public concern for conservation only emerged after this event, as there were already existing efforts and movements aimed at protecting wildlife and habitats prior to the extinction of the passenger pigeon.
Read my rebuttal of the other Patrick Moore chapters here:
Exposing Patrick Moore
Patrick Moore Credibility
Chapter 1 Fact-check: Baobab Trees
Chapter 2 Fact-check: Coral Bleaching
Chapter 3 Fact-check: Carbon Dioxide
Chapter 4 Fact-check: Polar Bears
Chapter 5 Fact-check: Estimated Threats to Biodiversity
Chapter 6 Fact-check: The Great Pacific Garbage Patch
Chapter 7 Fact-check: Genetically Modified Foods
Chapter 8 Fact-check: Nuclear Radiation
Chapter 9 Fact-check: Wildfires
Chapter 10 Fact-check: Ocean Acidification
Chapter 11 Fact-check: Walruses