Wednesday, January 21, 2009
January 22, 2009 - 7:42AM
MORE of Antarctica is heating up than scientists had thought.
A large part of West Antarctica, not just the peninsula area, has warmed during the past 50 years, a study shows.
The issue of climate change on the frozen continent has been controversial because East Antarctica has been cooling and temperature records are sparse.
Eric Steig, of the University of Washington, said his research showed that, overall, warming had outweighed cooling.
"The thing you hear all the time is that Antarctica is cooling. But it's more complex than that," Professor Steig said. "Antarctica isn't warming at the same rate everywhere and, while some areas have been cooling for a long time, the evidence shows the continent as a whole is getting warmer."
Warming in West Antarctica exceeded 0.1 degrees a decade during the past 50 years, similar to the rest of the world, the study, published in the journal Nature, said.
"Significant warming extends well beyond the Antarctic Peninsula to cover most of West Antarctica, an area of warming much larger than previously reported," Professor Steig said.
The research was based on 50 years of temperature measurements from weather stations, 25 years of satellite observations and a statistical analysis of the link between the two sets of data.
Professor Barry Brook, of the University of Adelaide, said the finding was alarming because it suggested the ice sheet in West Antarctica was at greater risk of melting.
Along with the Greenland ice sheet, a complete melt of both sheets would raise sea levels by 14 metres.
"Even losing a fraction of both would cause a few metres this century, with disastrous consequences," Professor Brook said. "I worry, with the observed polar warming over the last few decades and more in the pipeline due to lags in the climate system, that their large-scale melt is now a fait accompli."
Professor Steig said that the hole in the ozone had contributed to the cooling of East Antarctica but that it could close up by the middle of the century.
"If that happens, all of Antarctica could begin warming on a par with the rest of the world."
Another study, also published in Nature, has found that the seasons are starting about a 1.7 days earlier on average around the globe than during the first half of the century.
AAP reports: "[It's] bad news if you live near the Australian coast," Professor Brook said.
"In some areas where you've currently got housing, you'd probably have to abandon those areas."
He said the sea would penetrate up to one kilometre inland in flat areas such as South Australia's lower lakes.
Large areas which don't see flooding now would get flooded by king tides.
House prices for coastal areas would probably drop, Professor Brook said.