Sea levels this century may rise several times higher than predictions made in 2007 that form the scientific foundation for policymakers today, the meeting heard.
In March 2007, the UN’s Intergovernmental Panel on Climate Change (IPCC) concluded that global warming, if unchecked, would lead to a devastating amalgam of floods, drought, disease and extreme weather by the century end.
The world’s oceans would creep up 18 to 59 centimetres (7 to 23 inches), enough to wipe out several small island nations, and wreak havoc for tens of millions living in low-lying deltas in east Asia, the Indian subcontinent and Africa.
But a new study, presented at the Copenhagen meeting on Tuesday, factored in likely water runoff from disintegrating glaciers in Greenland and Antarctica, and found the rise could be much higher.
The IPCC estimate had been based largely on the expansion of oceans from higher temperatures, rather than meltwater and the impact of glaciers tumbling into the sea.
Using the new model, “we get a range of sea level rise by 2100 between 75 and 190 centimetres when we apply the IPCC’s temperature scenarios for the future,” said climate expert Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research.
Even if the world manages to dramatically cut the emission of greenhouse gases driving global warming, the ‘best estimate’ is about one metre (3.25 feet), he said.
“A sea level rise of one or two meters would not just be damaging for China, it would be an absolute catastrophe. And what is catastrophic for China is catastrophic for the world,” he said.
Up to 600 million people living close to coast lines in poor and rich countries alike could be affected, said Konrad Steffen, head of the Cooperative Institute for Research in Environmental Sciences in Boulder, Colorodo.
“They will have to move — it would change the whole structure of populations, and we know had badly we deal with migration,” he told AFP.
Among the worst hit countries will be Bangladesh, which would lose some 17 percent of its landmass, displacing nearly 15 million people. Afp