Poles apart but warming greater than thought

Marian Wilkinson Environment Editor, smh.com.au, February 27, 2009

Icebergs float in a bay off Ammassalik Island, Greenland.
 Photo: AP/John McConnico

A TWO-YEAR research effort by the world's leading scientists has uncovered evidence of global warming's widespread effect.

Snow and ice continue to decline in the Arctic and parts of Antarctica, affecting sea-level rise and weather patterns, as well as human, animal and plant life.

The findings of International Polar Year, a global research project involving 60 nations, were released yesterday. They confirmed that warming in Antarctica was greater than previously understood and the rate of ice loss from Greenland was increasing.

Dr Ian Allison, of the Australian Antarctic Division, who co-chaired the project told the Herald the effect of global warming in Greenland was clear.

"In Greenland the rate of ice loss is getting greater over the last 10 years and the surface [ice] melt is definitely related to the warming," Dr Allison said.

The project's scientists summed up their findings, saying: "It now appears certain that both the Greenland and the Antarctic ice sheets are losing mass and thus raising sea level, and that the rate of ice loss from Greenland is growing."

They also warned "the potential for these ice sheets to undergo further rapid ice discharge remains the largest unknown in projections of the rate of sea-level rise by the [United Nations] Intergovernmental Panel on Climate Change".

Projections for the NSW coast released by the State Government suggest sea levels are expected to rise up to 40 centimetres by 2050 and 90 centimetres by 2100. One centimetre of sea-level rise can have erosion effects of up to one metre in low-lying areas.

The popular belief that Antarctica may be resistant to global warming has been undercut by International Polar Year's research. Data from satellites and weather stations confirmed that for the past 50 years it has been warming at the same rate as the rest of the planet.

Until recently it was only the fragile Antarctic Peninsula that juts up from West Antarctica, which was considered vulnerable to global warming. The peninsula is warming more rapidly than much of the rest of the world with temperatures rising 2.5 degrees in the past 50 years and ice loss increasing 140 per cent in the past decade.

The recent research confirms the Arctic sea ice shrank last year to its second-lowest extent since satellite monitoring began in 1979. The previous low was the summer of 2007. Some scientists are predicting there will be an ice-free Arctic in summer by 2012.

Since the findings by the UN Intergovernmental Panel on Climate Change in 2007, it has been widely accepted that the planet's warming is almost certainly due to greenhouse gases being released from the burning of fossil fuels, land clearing and cement manufacturing.

The new research warns greenhouse emissions could rapidly increase from the Arctic warming. The Arctic contains large amounts of greenhouse gas that has been locked in permafrost and below the Arctic Ocean.