This is one of the pet (no pun intended) topics of the AGW alarmists. This is one thing that Al Gore might legitimately claim he invented. And Coca Cola recently launched a cuddly campaign to save the polar bear (see: WWF and The Coca-Cola Company Team Up to Protect Polar Bears). Since many other claims of the AW crowd have been shown to be alarmist or false, we thought we would take a look at this one.
Like most real issues, this one is complex. A short 3-page article in Canadian Geographic by Zac Unger, The truth about polar bears, gives a good overview of the issues involved in trying to ascertain the health and direction of polar bear populations. Forget any climate change connection for the moment. Considerations include:
- Polar bears live in a number of countries and jurisdictions (provinces and territories in Canada) with about 60% in Canada.
- There are many sub-populations or groups that are adapted to widely different environmental conditions.
- Accessibility to the different sub-populations varies widely by country and location.
- Methodologies for monitoring populations and health vary and attention must be given to keeping them minimally invasive.
- As a result of these and other factors, data sets may be mutually inconsistent and incomplete.
- Polar bears are widely hunted by aboriginal peoples and Western sports hunters.
To talk of species endangerment and protection seems absurd to us while hunting of the species is tolerated. Of course this opens up the minefield of politically correct respect for “traditional” native practices (hunting) and inevitably, so-called native rights. We note that in all such discussions there is nothing traditional about using snowmobiles to run down and high-powered rifles to kill animals.
In our recent post, Global Warming Update, we referred to climatic cycles in reference to the viability of models. In short, if you can’t model the range of cycles from decadal to the longer cycles of glaciation, you don’t understand climate and your models are mostly worthless.
Similarly, to talk about the effects of climate on polar bear populations is to speak ignorance if you can’t speak of how the populations handled comparable warm periods of the past, specifically the Roman and Medieval Warm Periods shown in the graph below:
(Source: Yet another paper demonstrates warmer temperatures 1000 years ago and even 2000 years ago. published by Watts Up With That? Click to open in new window)
A more recent paper (in Ecology and Evolution, 2016) is: Demographic and traditional knowledge perspectives on the current status of Canadian polar bear subpopulations. Here’s the abstract (emphasis added):
Subpopulation growth rates and the probability of decline at current harvest levels
were determined for 13 subpopulations of polar bears (Ursus maritimus) that are
within or shared with Canada based on mark–recapture estimates of population
numbers and vital rates, and harvest statistics using population viability analyses
(PVA). Aboriginal traditional ecological knowledge (TEK) on subpopulation trend agreed with the seven stable/increasing results and one of the declining results, but disagreed with PVA status of five other declining subpopulations. The decline in the Baffin Bay subpopulation appeared to be due to over-reporting of harvested numbers from outside Canada. The remaining four disputed subpopulations (Southern Beaufort Sea, Northern Beaufort Sea, Southern Hudson Bay, and Western Hudson Bay) were all incompletely mark–recapture (M-R) sampled, which may have biased their survival and subpopulation estimates. Three of the four incompletely sampled subpopulations were PVA identified as nonviable (i.e., declining even with zero harvest mortality). TEK disagreement was nonrandom with respect to M-R sampling protocols. Cluster analysis also grouped subpopulations with ambiguous demographic and harvest rate estimates separately from those with apparently reliable demographic estimates based on PVA probability of decline and unharvested subpopulation growth rate criteria. We suggest that the correspondence between TEK and scientific results can be used to improve the reliability of information on natural systems and thus improve resource management. Considering both TEK and scientific information, we suggest that the current status of Canadian polar bear subpopulations in 2013 was 12 stable/increasing and one declining (Kane Basin). We do not find support for the perspective that polar bears within or shared with Canada are currently in any sort of climate crisis. We suggest that monitoring the impacts of climate change (including sea ice decline) on polar bear subpopulations should be continued and enhanced and that adaptive management practices are warranted.