Times of India , 24 March 2006
Sea levels could rise by
six metres: Study
WASHINGTON: The Arctic and Antarctic ice
sheets could melt more quickly than previously thought, boosting sea levels
by up to six metres by 2100, according to a US study.
That would raise oceans to levels last seen
nearly 130,000 years ago, because of warmer Arctic temperatures caused by
greenhouse gases, scientists at the National Centre for Atmospheric Research
(NCAR) and the University of Arizona said in a paper in the journal Science.
The last time temperatures were that high, sea
levels rose by up to six metres, according to the study funded by the
National Science Foundation, an independent federal agency created by the US
"The ice sheets have melted before and sea
levels rose. The warmth needed isn't that much above present conditions,"
said NCAR researcher Bette Otto-Bielsner.
In the past few years, sea levels have risen
rapidly at a rate of 2.5 centimetres per decade, said co-author Jonathan
The scientists calculated their research with a
model that simulates past, present and future climates by analysing data of
previous temperature rises in the Earth's history which are recorded in ice
cores and coral reefs.
Looking at data from the period between the last
two Ice Ages, the researchers concluded that one factor that contributed
strongly to rising sea levels was that Arctic warming and melting eventually
led to a collapse of Antarctic ice sheets.
If the same happened today, this process would
only be accelerated by the fact that greenhouse gases have led to higher
global temperatures year-round, the scientists said.