Sydpolen – det sted på jordkloden som har været bedst beskyttet mod klimaændringerne – er kommet mere i farezonen. Ny satellit-overvågning når frem til, at den kolde verdensdel nu mister 160 milliarder tons is om året til det omgivende hav – dobbelt så meget som ved forrige undersøgelse.
The new assessment comes from Europe’s Cryosat spacecraft, which has a radar instrument specifically designed to measure the shape of the ice sheet.
The melt loss from the White Continent is sufficient to push up global sea levels by around 0.43mm per year, writes BBC online Monday.
The new study incorporates three years of measurements from 2010 to 2013, and updates a synthesis of observations made by other satellites over the period 2005 to 2010.
The study authors divide the continent into three sectors – the West Antarctic, the East Antarctic, and the Antarctic Peninsula, which is the long finger of land reaching up to South America.
Overall, Cryosat finds all three regions to be losing ice, with the average elevation of the full ice sheet falling annually by almost 2 cm.
The East had been gaining ice in the previous study period, boosted by some exceptional snowfall, but it is now seen as broadly static in the new survey.
As expected, it is the western ice sheet that dominates the reductions.
Here six huge glaciers are currently undergoing a rapid retreat – all of them being eroded by the influx of warm ocean waters that are drawn towards the continent by stronger winds whipped up by a changing climate.
About 90 oer cent of the mass loss from the West Antarctic Ice Sheet is going from just these few ice streams.
A loss of all the ice in the six glaciers would add about 1.2 meters to global sea level.
Mere om Sydpolen på http://en.wikipedia.org/wiki/Antarctica
