This may come as a shocker to some, but scientists are not always right — especially when under intense public pressure for answers.
Researchers with the IUCN Polar Bear Specialist Group (PBSG) recently admitted to experienced zoologist and polar bear specialist Susan Crockford that the estimate given for the total number of polar bars in the Arctic was “simply a qualified guess given to satisfy public demand.”
Crockford has been critical of official polar bear population estimates because they fail to include five large subpopulations of polar bears. Due to the uncertainty of the populations in these areas, PBSG did not include them in their official estimate — but the polar bear group did include other subpopulation estimates.
PBSG has for years said that global polar bear populations were between 20,000 and 25,000, but these estimates are likely much lower than how many polar bears are actually living in the world.
“Based on previous PBSG estimates and other research reports, it appears there are probably at least another 6,000 or so bears living in these regions and perhaps as many as 9,000 (or more) that are not included in any PBSG ‘global population estimate,’” Crockford wrote on her blog.
“These are guesses, to be sure, but they at least give a potential size,” Crockford added.
PBSG disclosed this information to Crockford ahead of the release of their Circumpolar Polar Bear Action Plan in which they intend to put a footnote explaining why their global population estimate is flawed.
“As part of past status reports, the PBSG has traditionally estimated a range for the total number of polar bears in the circumpolar Arctic,” PBSG says in its proposed footnote. “Since 2005, this range has been 20-25,000. It is important to realize that this range never has been an estimate of total abundance in a scientific sense, but simply a qualified guess given to satisfy public demand.”
“It is also important to note that even though we have scientifically valid estimates for a majority of the subpopulations, some are dated,” PBSG continues. “Furthermore, there are no abundance estimates for the Arctic Basin, East Greenland, and the Russian subpopulations.”
“Consequently, there is either no, or only rudimentary, knowledge to support guesses about the possible abundance of polar bears in approximately half the areas they occupy,” says PBSG. “Thus, the range given for total global population should be viewed with great caution as it cannot be used to assess population trend over the long term.”
PBSG’s admission also comes after academics and government regulators have touted their polar bear population estimates to show that polar bear numbers have grown since the 1960s. PBSG estimates have also been used to show that polar bear populations have stabilized over the last 30 years.
Polar bear populations became the centerpiece of the effort to fight global warming due to claims that melting polar ice caps would cause the bears to become endangered in the near future. Years ago, some scientists predicted the Arctic would be virtually ice free by now.
Polar bears became the first species listed under the Endangered Species Act because they could potentially be harmed by global warming. But some recent studies have found that some polar bear subpopulations have actually flourished in recent years.
“So, the global estimates were… ‘simply a qualified guess given to satisfy public demand’ and according to this statement, were never meant to be considered scientific estimates, despite what they were called, the scientific group that issued them, and how they were used,” Crockford said.
“All this glosses over what I think is a critical point: none of these ‘global population estimates’ (from 2001 onward) came anywhere close to being estimates of the actual world population size of polar bears (regardless of how scientifically inaccurate they might have been) — rather, they were estimates of only the subpopulations that Arctic biologists have tried to count,” she added.