May 21, 2019
To the United States Congress
I am an ecologist and was the director of San Francisco State University’ Sierra Nevada Field Campus for 25 years. My professional career was dedicated to promoting wise environmental stewardship. Despite my years of research to advance biodiversity, I’m gravely concerned about the recent Summary for Policymakers by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), where it suggests that 1± million species are now threatened with extinction. Based on my experience, that number is greatly exaggerated. It appears this organization grossly overstated species threats in order to promote their stated agenda that “goals for 2030 and beyond may only be achieved through transformative changes across economic, social, political and technological factors.”
The International Union for the Conservation of Nature (IUCN) is considered the gold standard for identifying threatened species. As of 2019, they estimate that there are 1,733,200 described species (not total species) of which less than 10% (just 98,512) have been evaluated to some degree. Of those evaluated species 27,159 species appear threatened with extinction to some degree. That is a reason for concern, but the IUCN estimates of species loss are a far cry from a million.
The IPBES suggested that the total number of threatened species could be derived by calculating the proportion of yet-to-be-evaluated species, using the same proportion of evaluated species that are considered threatened. Still such speculative math would still only result in 461,621 threatened species — again quite a few less than a million.
To reach 1± million threatened species the ≈ stated, “The proportion of insect species threatened with extinction is a key uncertainty, but available evidence supports a tentative estimate of 10 percent.” They then state that insects comprise 75% of the known 8± million animal and plant species. However, that results in an estimate of 6± million insect species which 6 times greater than the scientific consensus. Such misleading exaggerations suggest this group has a hidden agenda.
A key understanding is that 75%± of all mammal, bird, reptile and amphibian extinctions have occurred on islands, and 86% of those extinctions were the result of introduced non-native species. Island species had not evolved the defenses needed to resist introduced rats, cats, and stoats. For example, in Hawaii, the introduction of mosquitos and avian malaria in the 1800s decimated Hawaii’s native birds.
Due to invasive species, 41%± of all highly threatened species (Endangered and Critically Endangered) now live on islands. The current threats to most island species are not the result of what humans are doing wrong today, but the result of introductions a century ago. Now aware of the problem, humans are trying to fix it.
Private conservation groups and public land managers are now working to eradicate invasive species, but those efforts require much more resources. If IPBES was truly concerned about protecting threatened species, they could simply fund these eradication efforts. There is no need for “transformative changes across economic, social, political and technological factors.”
Furthermore, the IUCN’s criteria for designating threatened species (the total of Critically Endangered, Endangered and Vulnerable species) allows for much subjectivity. That subjectivity allows for overstating a species condition which would inflate the threat. For example to classify a species as “Threatened,” all one needs is “an observed, estimated, inferred or suspected population size reduction” The magnitude of the reductions determines if a species is Vulnerable, Endangered or Critically Endangered. That criteria is accurate for well-studied species for which quantitative studies have been carried out. However many ICUN evaluations “have no quantitative data available on densities or abundance” from which to determine the threatened status. The population reduction is then just inferred or suspected.
An example of the problem with speculations is the Adelie Penguin. It was classified as a species of Least Concern in 2009, with a population of about 4± million individuals throughout Antarctica. They were up-listed to Near Threatened based on a 2010 climate modeling study that speculated global warming would reduce the sea ice they needed to rest on during the winter. However, after more intensive studies, researchers realized Adelie populations were actually increasing and had now doubled to 8± million individuals. Due to good quantitative studies, the IUCN reclassified Adelies as Least Concern again.
Speculation that a million species are threatened with extinction does not fully account for the conservation efforts that are improving species once they have been identified as Endangered. For example, our current hunting regulations have allowed many whale species to return from the brink of extinction. Humpback and Bowhead whales were listed as Endangered in the 1980s. They have now recovered and are listed as species of Least Concern. Quantitative studies allowed for wise hunting quotas that quickly reduced the threat to many species. Again, there is no need for a “transformative changes across economic, social, political and technological factors.”
Loss of habitat is a key factor that can result in species becoming endangered — and sometimes it is political decisions that can lead to these species threats.
For example, government attempts to promote biofuels based on speculations about climate change have disrupted ecosystems and threatened more species. The European Union-subsidized Palm Oil for years, resulting in the loss of tropical forest and threatening species like the Orangutans. Realizing their mistake, those subsidies will be withdrawn.
Another example is that subsidies for sugar cane as a biofuel has prevented the restoration of tropical forests in Brazil, and corn subsidies in the USA have encouraged corn plantation in the northern Great Plains disrupting prairie ecosystems and reducing aquifers.
Yet another situation is that subsidies for industrial wind energy have resulted in increased bird and bat mortalities, in addition to the well-documented eco-system disruption. These representative examples should make clear that “transformative economic and political changes” can cause more problems than they solve.
I urge Congress to carefully peruse the IPBES claims. Their assertion of a million threatened species does not stand up to scientific scrutiny. Their gross exaggerations appear to be a political gambit to control “transformative changes across economic, social, political and technological factors,” while offering very little to improve current efforts to protect biodiversity.
Jim Steele was the director of the Sierra Nevada Field Campus from 1984 to 2010. He was Principal Investigator of the U. S. Forest Service Neotropical Migratory Bird monitoring in Riparian Habitats on the Tahoe National Forest, performed two USGS Breeding Bird Surveys in the area, and initiated the successful Carman Valley Watershed Restoration project. Contact [email protected]