EDUARDO FREI BASE, Antarctica - With prehistoric Antarctic ice sheets melting beneath his feet, U.N. Secretary General Ban Ki-moon called for urgent political action to tackle global warming. The Antarctic Peninsula has warmed faster than anywhere else on Earth in the last 50 years, making the continent a fitting destination for Ban, who has made climate change a priority since he took office earlier this year. "I need a political answer. This is an emergency and for emergency situations we need emergency action," he said during a visit to three scientific bases on the barren continent, where temperatures are their highest in about 1,800 years.

Antarctica's ice sheets are nearly 1.5 miles thick on average -- five times the height of the Taipei 101 tower, the world's tallest building. But scientists say they are already showing signs of climate change. Satellite images show the West Antarctic ice sheet is thinning and may even collapse in the future, causing sea levels to rise.

Amid occasional flurries of snow, Ban flew over melting ice fields in a light plane, where vast chunks of ice the size of six-story buildings could be seen floating off the coast after breaking away from ice shelves. "All we've seen has been very impressive and beautiful, extraordinarily beautiful," he said late on Friday. "But at the same time it's disturbing. We've seen ... the melting of glaciers."

MELTING
Ban is preparing for a U.N. climate change conference in Bali, Indonesia, in December, which is expected to kick off talks on a new accord to curb carbon emissions after the Kyoto Protocol expires in 2012. Ban has focused strongly on the environment and held a climate change summit at the United Nations on the eve of the annual General Assembly gathering of world leaders.

On Saturday, he continued his South American tour at Chilean national park Torres del Paine, taking a helicopter tour over Patagonian ice fields that scientists say are melting fast. Ban was flown over a glacier marked by large cracks from ice that has melted and broken away. "(Climate) change is progressing much faster than I had thought," he said, calling on developed countries in particular to do more.

Ban, the first U.N. chief to visit Antarctica, was also due to visit the Amazon rain forest in Brazil, a leading force in developing biofuels from crops as an alternative to fossil fuels. Fears about climate change have fueled a boom in biofuels. Despite the controversy of diverting food crops into fuel production, Ban has said alternative energy sources are vital to addressing climate change.

Antarctica -- a continent with only about 80,000 temporary residents -- is 25 percent bigger than Europe and its ice sheets hold 90 percent of the fresh water on the Earth's surface.

(By Juan Jose Lagorio, Reuters, 10/11/2007)