Conservative MP Ryan Leef (Yukon) apparently doubts the scientific case for climate change and the affect it is having on polar bears. As Margaret Munro reports, the MP from Yukon Territory sent a school teacher constituent a letter arguing that polar bear populations have quadrupled in the past 40 years. As support, he provided a report from a trio of notorious global warming deniers.
What is the truth about polar bears?
Before we get to that, let's have a quick look at the materials Leef provided. The report by Armstrong, Green and Soon argues that models used to forecast climate do not have have any predictive capabilities. As support, they refer to another paper they wrote which says "The forecasts in the [IPCC] Report were not the outcome of scientific procedures. In effect, they were the opinions of scientists transformed by mathematics and obscured by complex writing... We have been unable to identify any scientific forecasts of global warming. Claims that the Earth will get warmer have no more credence than saying that it will get colder."
IPCC is, of course, the Intergovernmental Panel on Climate Change who produce reports summarizing the global scientific community's understanding of climate. In short, the trio accused climate scientists around the world of gross malpractice.
A Rebuttal to the report is available here. Suffice to say, the case that CO2 emissions lead to global warming is well-established. You can't deny the reality that CO2 causes global warming without denying the laws of physics.
Leef has, however, revealed that some of our assumptions about the climate debate are wrong. Apparently it is possible to live in the North and be a climate change denier (Leef is the MP for Yukon).
What might Leef learn about the impact of climate on polar bears if he looked a little harder? For this, we turn to the IUCN/SSC Polar Bear Specialist Group. IUCN (the International Union for the Protection of Nature) is an international organization supported by many governments, including Canada. The Polar Bear Specialist group produces scientific assessments on the status of the world's polar bear populations at intervals of about 5 years. The last assessment was in 2009. You can read it here -- skip along to page 31 for the good stuff. An overview of the scientific methods used to assess polar bear population numbers can be found here.
The report shows that of the 19 sub-populations of polar bears, 8 are declining, 3 are stable, and 1 is increasing. There are too few data on the other sub-populations to say. Thirteen of the sub-populations are within Canada or are on its borders. It is interesting to note that the one population that is growing (M'Clintock Channel) was reduced from 900 bears in the 1970s to less than 300 by spring 2000. A moratorium on hunting within that sub-population was established in 2001, and then later revised to 3 polar bears per year.
There are between 20,000 and 25,000 polar bears in the wild. The main source of food for polar bears is seals, which the bears hunt out on the Arctic sea ice during the sunlit months (much of the Arctic is dark during winter). The summertime sea ice extent has been shrinking steadily for the past 30 years or so (see graphic below), which is depriving bears of their most important source of food.
The report notes
"Warming-induced habitat degradation and loss are already negatively affecting polar bears in some parts of their range, and unabated global warming will ultimately threaten polar bears everywhere. However, threats to polar bears will occur at different rates and times across their range."
In the High Arctic the reduction of ice coverage may actually help polar bears for a period of time because more openings in the sea ice may lead to a higher seal population. However, as global warming progresses, the High Arctic sea ice, and polar bears, are expected to be under threat just like everywhere else. The scientists at the meeting concluded "...the greatest challenge to conservation of polar bears is ecological change in the Arctic resulting from climatic warming."
There was a brief uproar last year when a study conducted on behalf of the Government of Nunavut revealed a stable polar bear population between 2004 and 2001. This led some to conclude that polar bears are doing just fine. Andrew Derocher, an experienced polar bear scientist at University of Alberta, explained why this is not the case:
"What is critical in the latest report is the number of cubs and yearlings found, he explains. Those numbers are substantially down. According to the aerial survey — very few cubs were seen in the region where the survey took place — 50 cubs and 22 yearlings were observed. What’s more, average litter sizes were the lowest recorded in recent years amongst the three Hudson Bay subpopulations, suggesting that reproductive output in WH (western Hudson Bay) was poor in 2011, the aerial survey concluded in its summary of findings.
That suggests to Derocher something serious is going on. Derocher believes that two to five times more cubs were born in the 1980s through to the 1990s."
So, it would appear that Yukon MP Ryan Leef has a lot to learn about polar bears and climate change. Unfortunately, Leef is not the only climate-denying MP in Prime Minister Harper's Conservative caucus. Joe Oliver recently expressed his doubts.
The Parties to the 1973 Agreement on the Conservation of Polar Bears met for only the third time in Iqaluit, Canada, in 2011. The web site for the meeting has this to say:
"After a successful meeting in Tromsø, Norway, in 2009, hopes were high that the Parties would agree upon steps needed to mitigate the effects of climate warming and reduction of sea ice habitat on polar bears. Progress toward climate change mitigation was limited, however, because of Canada's official position regarding anthropogenic climate change, and because the US delegation chose not to support a statement on this topic.
Canadians would probably be surprised to learn that the Harper government's official position on climate change is preventing progress on polar bear conservation.