Washington: A climate model has predicted that global warming, combined with nuclear waste, may make the Arctic Ocean a polluted soup by the year 2070.
According to a report in New Scientist, Ola Johannessen, director of the Nansen Environmental and Remote Sensing Center in Bergen, Norway, and his colleagues, developed the model.
To better understand the dispersal of pollution in the Arctic Ocean, Johannessen’s team studied the spread of radioactive substances such as strontium-90 and caesium-137 from nuclear testing, bomb factories and nuclear power-plant accidents.
Measurements taken between 1948 and 1999 were plugged into a high-resolution ocean circulation model and combined with a climate model to predict Arctic Ocean circulation until 2080.
Their model confirmed that most pollutants, including pesticide, petroleum residue and nuclear fallout, are currently washed out into the north Atlantic by the Transpolar Drift.
But, perhaps not for much longer.
In a nuclear accident, more radioactive material would be contained in the Arctic Ocean for much longer.
In a “business-as-usual” scenario, in which atmospheric carbon dioxide levels double by 2070, Johannessen and his colleagues found that the Transpolar Drift stops and the Beaufort Gyre, Greenland Current and Gulf Stream weaken considerably.
One reason for this sluggish behaviour is a change in wind patterns driven by global warming and rapid melting of the Arctic sea ice.
As a result, pollution takes much longer to disperse in this scenario. Much of this pollution would congregate along the non-European coastlines of the Arctic Ocean, the model suggests.
According to Jeff Ridley of the Met Office Hadley Centre in Exeter, UK, surface circulation in the Arctic Ocean will weaken if sea ice disappears, but he doubts it will happen quite so fast.
He also points out that other currents in the region would continue to disperse pollutants.