|
WELLINGTON, Dec. 13 (Xinhua) -- The melting of the Antarctic ice is set to amplify climate change globally, says a New Zealand Antarctic expert who took part in an international study of the warming of the frozen continent.
The researchers used computer models to investigate what would happen if pulses of meltwater were released by the Antarctic ice sheet into the Southern Ocean.
The models showed that although the influx triggered cooling of the sea surface around Antarctica, temperatures deeper in the ocean began to rise, Dr. Golledge of Victoria University said in a statement Tuesday.
"This response is well known, but what is less known is that the input of fresh water also leads to changes far away in the northern hemisphere, because it disrupts part of the global ocean circulation," said Golledge.
"This means that meltwater from the Antarctic ice sheet won't just raise global sea levels, but might also amplify climate changes around the world. Some parts of the north Atlantic may end up with warmer air temperatures as a consequence of part of Antarctica melting."
The team used its models to simulate how Antarctica and the global climate might have changed over the last 8,000 years, with Golledge using a computer model to simulate how the Antarctic ice sheet changed from the end of the last ice age to the present, warm period.
The study found that high-frequency changes in ocean temperatures tended to be absorbed by the Antarctic ice sheet, which then responded more slowly.
"Whilst this might be seen as a good thing, it also implies that once the ice sheet starts responding, by melting, it may be too late to prevent the consequences," said Golledge.
The researcher concluded that the Antarctic ice sheet played a major role in regional and global climate variability, a discovery that might help explain why sea ice in the southern hemisphere had been increasing despite the warming of the rest of the Earth.
Last year Golledge led another study and found that future ice melt from Antarctica could lead to sea-level rise up to 10 meters above present day if greenhouse gas emissions continued at present rates.
