Arctic Land Animals Lose Habitat Along With Sea Ice

B. McPherson

Ice caps are Earth's air conditioners

Sea ice in the Arctic Ocean is thinning and disappearing quickly. Each summer the ice retreats sooner and farther. The alarm has been sounded for those mammals that use the ice as haul out sites – seals, polar bears – but little attention has been given to the land animals that inhabit the Arctic tundra.

A new article published by Science and authored by Eric Post of the University of Penn State and Jedediah Brodie of the University of British Columbia as well as other contributors points out how the retreat of sea ice and the warming of the tundra will have a profound impact on the land based animals and plants as well. The land animals use frozen ocean sections as bridges. Warming of the tundra, melting the permafrost may create open swamps and lakes, thwarting the migration of animals like the caribou. The loss of these pathways means an increasing isolation of populations.

A rare but increasing phenomenon being seen of late is the interbreeding of grizzly and polar bears. Polar bears are spending an increasing time ashore and coming into contact with grizzlies. The result – grolars – an nightmare beast.

As more sea ice melts, the timing of alage blooms change. This throws off the timing of fish and sea birds as well. Do the migrating birds return too early or too late to slurp up the nutritious green soup? If the birds don’t thrive, the arctic foxes who prey on them don’t either and so on.

The retreating sea ice is not the only problem facing the Arctic. Warmer temperatures and drier conditions have set the scene for massive fires in the tundra. Wildfires in northern Saskatchewan and Manitoba are sending massive amounts of smoke curling north along the Hudson’s Bay. The sooty deposits land on the ice and encourage even faster melting.

Much of Canada’s and Russia’s north is an area of perma frost. While surfaces may thaw, the deeper soil layers remain frozen year round. As the Earth’s climate warms, the swampy areas thaw, releasing methane gas, a powerful greenhouse gas. This further encourages more melting.

Scientists are concerned about the far north because there is the possibility of a positive feedback loop being set up. Following is a very simplified version.

Air warms àmore ice melts àopen ocean is exposed, darker than white ice à more ice melts à ice melts on land faster à permafrost starts to melt, releasing methane à accelerating greenhouse gases àair warms àbrown earth absorbs more heat than snow covered à more ice melts

More information: Arctic News