Actually modeling of Polar Bear distribution in future has already been done. The population will shrink ca 30% until 2050 basing on climate warming not being stopped. Fits the Vulnerable status, a step lower than Endangered and less than many animals threatened by deforestation or poaching.
This had little interest to innumberable journalists and activists suggesting they will go extinct.
Well, I'm always in the market for good news, but I'm awfully familiar with models that don't take any, or sufficient, account of what turn out to be major factors (often because "we can't model that"). So I'd be interested to know which of the following were included as factors in the model:
Ice extent/duration each year including ability to bear weight of bear
Maximum distance a Polar Bear can swim (and effect on this of increasingly violent weather events)
Effect of changes of ice cover on prey availability due to effect on prey breeding, including not only total biomass but localisation of populations
Effect of hybridisation in the event of the whole Arctic landmass becoming available habitat to Grizzlies (hint: biggest population normally wins these)
Effect of predation on bears making more long swims than in the past by e.g. Orcas
Availability of snow dens for Polar Bear breeding
Infanticide by male bears confined in smaller territories by reduced ice as well as reduced prey availability
Fragmentation of populations leading to local extinctions (and more permanent separation of remainder as a result)
I also seem to remember hearing that Polar Bears have the highest levels of PCBs of any animal apart from St Lawrence Seaway Belugas and that this is held to have an effect on breeding success. Is that getting worse or better?
Finally, all the news is of climate change happening faster and more violently than anyone expected (or modelled, surprise surprise): does that in itself mean Polar Bear population modelling should be revisited rapidly?
I look forward to hearing all included, no problems. :t:
John