The Arctic sea-ice plays an important role in regulating the planet’s temperature, and any problems with this natural thermostat are a cause for concern. A private agency suggests the minimum extent of Arctic sea-ice is in the region of 13.1% per decade, based on the 1981 to 2010 average.
The Fourth Assessment Report of the Inter-Governmental Panel on Climate Change (IPCC) in 2007 concluded that increasing concentrations of greenhouse gases in the atmosphere as a result of human activity were primarily responsible for the decline in sea-ice extent in the region. The disappearance of sea-ice in a warming world also contributes to an increase in the mean surface temperature. Sea-ice is estimated to reflect 80% of sunlight back into space, meaning it does not heat the surface.
But when the sea-ice melts, the surface of the deep ocean is exposed, absorbing about 90% of the sunlight. Due to this, the temperature in the area is increasing. This phenomenon is known as the albedo effect, and occurs because light surfaces reflect more heat than dark surfaces.
The freezing and melting of the seas in the Arctic is a seasonal phenomenon, with the freezing point peaking in March and the melting point reaching its maximum in September. However, ground observations and satellite data tell us that the sea-ice extent in the Arctic polar region is decreasing as the planet warms.When this happens, the albedo (or reflectance) decreases, because deep-sea water absorbs more heat than lighter sea-ice. This, in turn, causes the land and the oceans to warm even more. Ultimately, scientists fear that increasing amounts of land in areas traditionally covered with snow will trigger a “tipping point.” This is where the warming of the atmosphere reaches a point where human intervention will no longer be able to stop it.