Climate Change

The Arctic is warming at least 2-3 times faster than the global average, due to multiple positive feedbacks within the Arctic system.  The best known of these is the ice albedo feedback – as the Arctic warms, sea ice, which has a very high albedo (reflectivity), melts, revealing open ocean, which has a quite low albedo, and thus absorbs more incoming solar radiation, causing further melting.  But it isn’t necessary to have complete melting – when the summer air temperature reaches above O deg. C the snowcover and the surface of the ice can melt to create melt ponds, which appear blue, and they too are quite low albedo.  

The area of sea ice in the Arctic Ocean region is diminishing, roughly linearly, with climate warming.  This then has an impact on life in the Arctic Ocean region, from the bottom to the top of the food chain.  Sea ice algae on the underside of sea ice provides nutrients for copepods and krill that thrive under the sea ice.  Baleen whales (Bowheads in the Arctic) filter and feed on that krill.  The retreat of sea ice impacts the migration of Bowhead whales, the hunting of which forms a significant basis for the subsistence hunting culture of the Inupiaq Eskimos along the North Slope and the Inuit in the Canadian Archipelago.  

Seal that create dens for their pups on the sea ice are disrupted, and the polar bears that feed on seals that seek refuge under the ice are disrupted.  On the tundra that surrounds the Arctic Ocean the spring snowpack melt season comes earlier, and the growing season is longer.  That impacts permafrost thawing, which could cause an increase of CO2 and CH4 emissions, representing another positive feedback mechanism.  

The loss of sea ice in the Canadian Archipelago has opened up opportunities for shipping through the “northwest passage.”  Ships burning bunker fuel emit black carbon particles that deposit onto the sea ice and snowpack, decreasing the albedo and representing another positive feedback in the Arctic.  Those ships, along with the existing oil and gas production regions around the Arctic emit CO2 and methane, and also nitrogen oxides that can impact the amount of ozone in the lower atmosphere.  The particles emitted from these anthropogenic sources can act as cloud condensation nuclei that then impact cloud cover and the brightness (albedo) of the clouds.  

One can see that humans are deeply impacting climate and the intricate web of life in the Arctic, and could ultimately take us past a point of “no return.” 

The web site arcticstories.net includes video interviews of residents of the Arctic and scientists who describe their passion for understanding this myriad of interconnected processes. On this website they discuss what they have seen about the impacts of climate change in the Arctic.  Perhaps these stories will help people understand the importance of decarbonizing the methods of global energy management so that we can act faster to save this fascinating region.