VIENNA — Melting glaciers, disappearing ice sheets and
warming water could lift sea levels by as much as 1.5 meters by the end of this
century, displacing tens of millions of people, new research showed on Tuesday.
Presented at a European Geosciences Union conference, the
research forecasts a rise in sea levels three times higher than that predicted
by the Intergovernmental Panel on Climate Change (IPCC) last year. The U.N.
climate panel shared the 2007 Nobel Peace Prize with former U.S. Vice President
Al Gore.
Svetlana Jevrejeva of the Proudman Oceanographic Laboratory
in Britain said the estimate was based on a new model allowing accurate
reconstruction of sea levels over the past 2,000 years.
"For the past 2,000 years, the sea level was very stable,"
she told journalists on the margins of the Vienna meeting.
But the pace at which sea levels are rising is accelerating,
and they will be 0.8-1.5 meters higher by next century, researchers including
Jevrejeva said in a statement.
Sea levels rose 2 cm in the 18th century, 6 cm in the 19th
century and 19 cm last century, she said, adding: "It seems that rapid rise in
the 20th century is from melting ice sheets".
Scientists fiercely debate how much sea levels will rise,
with the IPCC predicting increases of between 18 cm and 59 cm.
"The IPCC numbers are underestimates," said Simon Holgate,
also of the Proudman Laboratory.
The researchers said the IPCC had not accounted for ice
dynamics – the more rapid movement of ice sheets due to melt water which could
markedly speed up their disappearance and boost sea levels.
But this effect is set to generate around one-third of the
future rise in sea levels, according to Steve Nerem from the University of
Colorado in the United States.
"There is a lot of evidence out there that we will see around
one meter in 2100," said Nerem, adding the rise would not be uniform around the
globe, and that more research was needed to determine the effects on single
regions.
Scientists might debate the levels, but they agree on who
will be hardest hit – developing nations in Africa and Asia who lack the
infrastructural means to build up flood defenses. They include countries like
Bangladesh, almost of all of whose land surface is a within a meter of the
current sea level.
"If (the sea level) rises by one meter, 72 million Chinese people will be
displaced, and 10 percent of the Vietnamese population," said Jevrejeva.
