Jeg husker rapportene da isplatået Lars B brøt løs og drev av gårde fra Antarktis. Det var vanskelig å fatte at noe så stort kunne brekke og flyte. Nå sier vitenskapen at hele West Antarctica, som er en femtedel av Antarktis, er flytende og kan lide samme skjebne. FNs generalsekretær Ban Ki Moon var nylig på besøk og fikk se dimensjonene og høre advarslene.
The polar experts, studying the effects of global warming on the icy continent that is devoted to science, fear a repeat of the 2002 collapse of the Larsen B ice shelf. The 12,000-year-old shelf was 220 metres (720ft) thick and almost the size of Yorkshire.
«I was told by scientists that the entire Western Antarctica is now floating. That is a fifth of the continent. If it broke up, sea levels may rise as much as six metres,» Mr Ban said after being briefed at the Chilean, Uruguayan and South Korean bases during a day trip to King George Island, at the tip of the Antarctic Peninsula.
Gino Casassa, a Chilean member of the Nobel Peace Prize-winning Intergovernmental Panel on Climate Change, said: «The climate change here in the past ten years has been up to ten times the global average.»
The change was predicted by John Mercer, a glaciologist, he said. The late Dr Mercer, who worked at Ohio State University, theorised that the collapse of ice shelves along the Antarctic Peninsula could be a harbinger of the disintegration of the much larger West Antarctic Ice Sheet, which would raise global sea levels by six metres over the course of a century.
His warning was first published in the journal of the International Association of Scientific Hydrology in 1968, but attracted little attention until it was published in Nature magazine a decade later. Now it has the UN Secretary-General’s attention as he prepares for a UN climate change conference in Bali next month aimed at trying to agree limits on «greenhouse gas» emissions once the restrictions specified by the Kyoto Protocol expire in 2012. Before that Mr Ban will go to Valencia, in Spain, for the launch on Saturday of a fourth and final report by the Intergovernmental Panel on Climate Change, summing up the findings of the panel’s 2,500 scientists.
Ban Ki Moon kan virke stiv, men han er oppriktig engasjert i klimatrusselen.
«This is an emergency. For an emergency situation we need an emergency act,» Mr Ban said before his flight back to Chile. «We have resources. We have financing. Only lacking is political will.»