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Notizia climatica, alquanto allarmante

Alessandro Gimona

                Polar meltdown's terrifying
                pace

                Washington: Melting is taking place on a vast and
                unprecedented level in the Arctic sea ice, the
                Antarctic and in dozens of mountain and
                sub-polar glaciers, and the rate has accelerated
                tremendously in the past decade, a US
                environmental watchdog group has reported.

                The Worldwatch Institute in Washington says the
                shrinkage of the Earth's ice cover could have
                profound changes on the global climate, and
                rising sea levels could spark regional flooding.

                Melting of mountain glaciers could also threaten
                urban water supplies and the habitats of plant and
                animal species in fragile environments, the report
                added.

                The melting has been particularly noticeable in the
                past three decades, and scientists suspect it is the
                result of human behaviour and the build-up of
                carbon dioxide and other greenhouse gases.

                The Antarctic ice cover, which averages 2.3
                kilometres thick and represents 91 per cent of
                the world's ice, is also melting. Ice to the west of
                the Antarctic Peninsula decreased by some 20
                per cent between 1973 and 1993.

                The main front of New Zealand's Tasman Glacier
                has retreated 1.5 kilometres since 1982, the
                report said.

                The Arctic sea ice has shrunk by 6 per cent since
                1978, with a 14 per cent loss of the thickest
                year-round ice. The average thickness has
                dropped from 3.1 metres to 1.8 metres - a
                decline of nearly 40 per cent in the past three
                decades.

                The Greenland Ice Sheet, which comprises 8 per
                cent of the world's ice, has thinned by more than
                a metre per year on average since 1993 on its
                southern and eastern edges.

                The world's mountain glaciers are now shrinking
                faster than they are growing. Scientists predict
                that a quarter of global mountain glacier mass
                could disappear by 2050.

                Within the next 35 years, the Himalayan glacial
                area is expected to shrink by one-fifth, to just
                100,000 kilometres.

                In Glacier National Park, in the US Rocky
                Mountains, the number of glaciers has dropped
                from 150 to fewer than 50, Worldwatch says.

                The report predicts that the remaining glaciers
                could disappear in 30 years.

                Deutsche Press-Agentur
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