The rapid melting of the Arctic sea ice, then, illuminates the difficulty of modelling the climate but not in a way that brings much comfort to those who hope that fears about the future climate might prove exaggerated.
Since the total mass of the ocean and ice remains unchanged during the melting process, this has often led to the erroneous assumption that sea level will be unaffected by the melting of floating ice, say geologists David Holland and Adrian Jenkins.
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However, scientists do not fully understand the relationship between air and sea temperature, and the melting of ice.
In the Arctic, the oil giant is exploiting melting sea ice to drill for more of the oil causing global warming in the first place.
The melting of an ice shelf, which is merely a floating projection into the sea, would not affect sea levels.
The Arctic's importance has gained extra strategic and economic significance as melting ice in the polar region strengthens the feasibility of nations to use the Northern Sea Route (NSR) across the top of Russia and the Northwest Passage through Canada's Arctic archipelago.
This means that we can expect more than the one-meter sea level rise projected for 2100, a fact that the rapid melting of the Greenland ice sheet, as well as strong indications that the western part of the Antarctic ice sheet is also melting, strongly support.
To be more specific, the article discusses a study published in the journal Science states that higher temperatures over the past two decades have contributed to a nearly half-inch rise in global sea levels since 1992, attributing about 30% of that increase to melting of polar ice sheets.
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In fact, recent research by Blancon et al published in Nature in 2009, examining the paleoclimate record, shows sea-level rises of 3 metres in 50 years due to the rapid melting of ice sheets 123, 000 years ago in the Eemian, when the energy imbalance in the climate system was less than that to which we are now subjecting the planet.
That means more melting ice in the Arctic, dumping fresh water into the salty sea and making a mess of the all-important Gulf jet stream, which makes northern U.S. habitable.
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However, the fact that more ice rests below sea level means that on millennial timescales, increased amounts of ice are potentially vulnerable to ocean melting.
And now the Arctic's upper layers are getting less dense, for several reasons: melting Arctic glaciers, rising surface-water temperatures, increased precipitation and an absence of salt concentrations resulting from sea-ice formation.
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