Sea levels are rising 60 percent faster than U.N.
projections, threatening low-lying areas from Miami to the
Maldives, a new study says.
The report, issued during U.N. talks in Qatar on combating
climate change, also said temperatures were creeping higher
in line with U.N. scenarios, rejecting hopes the rate had
"Global warming has not slowed down, (nor is it) lagging
behind the projections," said Stefan Rahmstorf, lead author
at the Potsdam Institute for Climate Impact Research that
compared U.N. projections to what has actually happened from
the early 1990s to 2011.
The study said sea levels had been rising by 3.2mm a year
according to satellite data, 60 percent faster than the 2mm
annaul rise projected by the U.N.'s Intergovernmental Panel
on Climate Change (IPCC) over that period.
"This suggests that IPCC sea-level projections for the future
may also be biased low," the authors from Germany, France and
the United States wrote in the journal Environmental Research
The IPCC's latest report in 2007 said seas could rise by
between 18cm and 59cm this century, not counting a possible
acceleration of the melt of the Greenland and Antarctic ice
sheets that could add more still water to the oceans.
In the last century, seas rose by about 17cm.
Rahmstorf told Reuters his best estimate for sea level rise
was between 50cm and a metre this century, possibly more if
greenhouse gas emissions surged. Higher temperatures would
melt more ice on land and expand the water in the oceans.
That would leave low-lying regions - from Pacific island
states and Bangladesh to Tokyo and New York - facing a
greater risk of storm surges, erosion and, in a worst case
scenario, complete swamping by flood waters.
The IPCC was criticised after it had to correct parts of its
2007 report that exaggerated the rate of melt of Himalayan
glaciers and wrongly said they might vanish by 2035.
People sceptical that man-made emissions of greenhouse gases
are stoking climate change also wonder if warming has
flattened out. They note that 1998, 2005 and 2010 are tied as
the warmest years since records began in the mid-19th
But the study said overall warming was in line with IPCC
projections of a gain of 0.16degC a decade from 1990 to
2011, after correcting for natural variations caused by
volcanic eruptions, El Nino events that warm the Pacific and
shifts in the sun's output.
Almost 200 nations are meeting in Doha from November
26-December 7 as part of floundering efforts to work towards
a U.N. deal to curb global emissions of greenhouse gases from
"Unless we reduce our carbon pollution rapidly, this study
clearly shows we are heading for the nightmare world at the
top end of the IPCC predictions," said professor Mark Maslin
of University College, London.
The IPCC says rising temperatures could cause more floods,
droughts, heatwaves, mudslides and desertification that would
strain water and food supplies for a rising world population.
"The authors have stressed what many of us have thought for
some time - the IPCC is far from alarmist in its
projections," said Professor Sir Brian Hoskins, Director of
the Grantham Institute for Climate Change at Imperial