Albedo is a term that is utilized to refer to the measure of a given land surface to reflect solar radiation back towards space.  Snow, for instance, has a high albedo because it reflects 85%-90% of incoming sunlight.  While vegetation and dark soil, by comparison, have low albedos because they reflect only about 20% of incoming sunlight back towards space.  In the Arctic, nowadays, temperatures are rising faster than the world average because global warming is decreasing the overall amount of snow and ice cover, which decreases the albedo of the Arctic surface area and, in turn, increases the amount of solar radiation that the Arctic absorbs, resulting in a self-reinforcing Arctic warming feedback loop. 

Albedo physics, view	Arctic warming feedback loop, view

Albedo dynamics in the Arctic region, now being transformed by an Arctic warming feedback loop, are mutating the energy balance of our global climate system.  This unfortunate course of events, sparked by human pollution of the atmosphere, is near irreversible on a timescale meaningful to humanity.  Yet nature does have internal buffering mechanisms which could partially offset and slow this trend.  For instance, in accordance with the warming temperatures and lengthening growing season in the Arctic, forests are now spreading north to colonize Arctic areas, these forests are more effective than tundra at sequestering airborne CO2, and thus they have the potential to help stem climate change.  A welcome novelty, yes, however albedo dynamics are still going to be the stronger relative driver of climate change.

Snow-cover fluctuations in the Northern Hemisphere have been monitored by satellites for decades.  The data sets from the satellites show that the mean monthly snow-cover extent in the Northern Hemisphere has decreased substantially since the 1960s, with the greatest losses in the spring and summer months.  This widespread retreat of snow-cover, which keeps the Arctic cold, is a sensitive indicator of world climate change and a warning of environmental changes to come.  In Canada, the Inuit corroborate that average amounts of snow-cover are declining, especially in the spring time, and this matter concerns many Inuit.

The disappearance of snow-cover in Nunavik, because of its implications for the albedo of the land surface, is a causal instigator of accelerating and unshakable regional temperature increases.  On a larger-scale, the difference in Nunavik’s snow-cover is also impacting the global distribution of heat via air and ocean circulation.  Quite simply, snow-coverage albedo dynamics matter.  In Alaska, the largest American state, for example, scientists attribute 95% of a recent summer warming trend to a decline in snow-cover duration. Ominously, global climate models now predict that much of the Northern Hemisphere may lose up to 98% of its traditional annual snow-coverage by the year 2100 -- that reality is thus projected to occur within the lifespan of some people now alive today.