A couple days ago I heard the news that Charles Monnett (an Arctic Wildlife biologist) was forced to retire as part of a settlement with a federal agency. Charles Monnett, together with Jeffrey Gleason, became known for spotting four dead polar bears after a storm in 2004 while studying bowhead whales and publishing a paper in the journal Polar Biology on these observations. This was explained by the media as proof of the negative influence of global warming on polar bears.
I remember it well. I was still a believer at the time and I found this “evidence” worrying. Believing in the validity of the results of this paper, I took this as proof that polar bears were not doing well because of our emissions. Adding to the overwhelming evidence of the wrongdoing by us, humans. I heard it and believed it was true, maybe somewhat exaggerated, but true nevertheless.
In 2011 Monnett was being investigated by the Interior Department’s Inspector General’s office, culminating into his retirement now. Reading about this I came across several comments that wrote that the paper in itself was not alarmist in nature. In 2011 I wasn’t really interested to look into it. Now it seems a nice moment to look into it, seeing what it was based on and how the media was broadcasting it. Just to see if my trust in this result was justified nine years ago.
The paper was quickly found. Indeed, it was not really an alarmist paper. What it basically said was that, although polar bears are good swimmers, they seen more swimming bears (almost 20%) than was observed in the past (almost 4%). Less ice means an increase in wave height and with more swimming bears that have to swim over a larger distance this could mean more drownings. Especially for mothers (with cubs). After a storm they found dead polar bears during their survey, something they claim wasn’t observed in the past (this could have other explanations though: considering that they themselves made the observation by chance, sampling bias comes to mind).
An interesting part of the paper was the “creative” calculation of the survival rate of the (swimming) polar bears. This is how it was done:
Only a small total number of bears was seen on > 14,000 km of transect surveyed in 2004, thus limiting our ability to provide accurate estimates of polar bear mortality and associated confidence intervals (see McDonald et al. 1999; Evans et al. 2003). If, however, data are simply spatially extrapolated, bear deaths during a period of high winds in 2004 may have significant. Our observations obtained from 34 north-south transects provide coverage of approximately 11% of the 630 km wide study area assuming a maximum sighting distance for swimming/floating polar bears of 1 km from the aircraft (coverage = 630 km/ (34 transects x 2 km wide transect) = 10.8/ of study area). Limiting data to bears on transect and not considering bears seen on connect and search segments, four swimming polar bears were encountered in addition to three dead bears. If these bears accurately reflect 11% of bears present under these conditions, then 36 bears may have been swimming in open water on 6 and 7 September, and 27 bears may have died as a result of the high offshore winds. These extrapolations suggest that survival rate of bears swimming in open water during this period was low (9/36 = 25%).
Basically they said:
- 11% of the area was surveyed
- 4 bears were seen swimming in this area between 6 – 8 September 2004. Meaning 4 x 100/11 ≈ 36 bears swimming
- 3 dead ones were seen from 14 September 2004 (there was also another dead bear in another area, so in total 4 observed, but 3 in the surveyed area). Assuming those 3 were from the 4 swimming bears, meaning 3 x 100/11 ≈ 27 bears dead
- Result: 36 swimming bears – 27 dead ones = 9 survived the storm.
- 9/36×100 = 25% survival rate of the swimming polar bears.
All those calculations were not even needed: in their assumption that the covered transects are representative for all the others, then 1 bear survived out of 4, meaning 25%. But 3 dead bears is not impressive compared to the virtual 27 deaths from the calculation.
This was based on a very, very small number of observation (ahem, n=4) and based on a load of assumptions. More, the pictures taken as evidence seemed to contain just some blurry white spots in a blue ocean. Hey, most Big Foot footage is more detailed than these photographs. While the other pictures (of bowhead whales) apparently were more clear. Mmmmmh.
A lot of questions arise. Since 2004 the Arctic ice pack diminished even further and got its lowest value in 2012. If polar bears are drowning in droves, where are the pictures of floating dead polar bears? If there are more swimming polar bears and a survival rate of 25%, where is the evidence for dramatic population declines? If less ice means more swimming and swimming means more drowning and these were the first to be observed, why are there no drowned bears observed in the 1995/7 when there were observations of bears much further away from the ice? Even if these where really dead polar bears, how can such a small set (4 observations in a small area) say something about a global population of 20,000-25,000? Wasn’t this an special event in which it is “likely the creatures drowned in a sudden windstorm that produced 30-knot winds, not for lack of an ice pack” as Gleason acknowledged in the Inspector General interview? Assuming of course that those white dots in the ocean were actual dead polar bears and not for example debris from the storm.
Not really the strong evidence I was expecting to find.
Monnet and Gleason were saying they didn’t mention global warming in the paper, which is correct. They stated that “to date, mortality due to swimming has not been identified as an associated risk” (of course not, they were the first to observe this), but “may become important in the future if the Arctic pack ice continues to regress”. However, alarmist minds should have no difficulty filling in the global warming story line in here.
And filling in they did. Al Gore talked about it in An Inconvenient Truth:
That’s not good for creatures like polar bears that depend on the ice. A new scientific study shows that for the first time they’re finding polar bears that have actually drowned, swimming long distances up to 60 miles to find the ice. They did not find that before.
Complete with a heartbreaking animation of a polar bear that is desperately trying to get on an ice shelf, but it breaks with every try. So, not only the assumption disappeared, but the anecdotal evidence was declared as absolute truth and seamlessly connected with, gasp, global warming. No word about the storm either. It makes it appear as if the polar bears drown because they just can not find any ice anymore. This deperate bear in a vast ocean with nothing to hold on is of course a powerful image and will give an emotional response with many. But when looking at it in the light of its information value, the portrayed image is not true.
The mainstream media did basically the same. Although Monnett and Gleason didn’t attributed the shrinking ice pack directly to global warming, the media had no problem at all to fill in the gap. Most also didn’t mention the storm and attributed the drowned bears directly to global warming.
It didn’t stop there. The paper was cited by the U.S. Fish and Wildlife Service in its 2008 decision to list the polar bear as threatened under the Endangered Species Act.
Although the paper could only give anecdotal evidence, included creative “statistics” and was based on a load of assumptions, it apparently had quite some influence. Nine years ago I trusted that this poor “survival rate” of (swimming) polar bears was rooted in some serious science. This trust I had back then seemed not justified. In the end, it was not the paper that made the connection between drowned bears and global warming. It was indeed Al Gore and the media that made this up.
Trust, yet verify 