The Great Arctic Meltdown  

This year's Arctic ice melt hasn't been as great as last year's record breaking event, but there are still people predicting the Arctic could be (periodically) ice free by 2013 - Voyage into the Arctic as summer ice vanishes.

THE vast Arctic sea ice which spreads across the North Pole could disappear during the summer within a decade or two - or even by 2013 - leading scientists are warning.

The Canadian Coast Guard's strongest icebreaker, the Louis S. St Laurent, took the Herald and an ABC Four Corners crew with a team of scientists going to the Arctic at the beginning of this summer's melt in July to explore the extraordinary changes there first hand.

Only a few years ago, climate modellers predicted the sea ice would not disappear in summer until at least the end of the century. "Then they said 2070, and then they said 2050 and then they said 2030," said Robie Macdonald, a leading Canadian oceanographer on board the Louis. "Not only do I see the change, but it's like they're moving the goalposts toward me and it's an amazing thing," he said.

The team on board the Louis are some of the thousands of scientists from 60 nations working to draw attention to the rapid changes in the Arctic and Antarctic during International Polar Year.

The icebreaker's route took us through thick sea ice at the entrance to the fabled Northwest Passage where over the centuries many navigators perished, most famously Sir John Franklin, a former governor of Tasmania.

Last year the Northwest Passage was virtually ice free for the first time in memory when the Arctic sea ice shrank to its lowest level since satellite observations began.

The US Interior Secretary, Dirk Kempthorne, announced in May the drastic loss of Arctic sea ice had forced him to list the polar bear as an endangered species because their populations could collapse within a few decades.

Hopes the sea ice would return to robust levels after last year's record low are unlikely to be realised, according to the latest figures from the US National Snow and Ice Data Centre. While this year's melt is not expected to shatter last year's record, the sea ice is already significantly below average as the melt season peaks.

"We might see an ice-free Arctic Ocean by the year 2030 - within some of our lifetimes," said Mark Serreze, a geographer at the snow and ice data centre. "There are some scientists out there who think that even might be optimistic."

While Australians argue about when or whether to confront global warming, the top of the globe is melting away.

The Arctic sea ice – sprawled across an area roughly the size of Australia - is in retreat. Scientists now fear that in less than 25 years from now, for the first time in human existence, there will be no sea ice in the North Pole in parts of the summer.

These scientists are scrambling to model and measure the pace of the melt and to comprehend the enormity of the consequences – not just for the immediate ecosystem of polar bears and plankton, but for the world’s weather and its ability to feed itself.

At the same time governments and corporations scramble to be first at the table for a new resources feast of oil, gas and minerals. It’s being dubbed a "Cold Rush" as retreating sea ice opens new opportunities and faster, cheaper shipping routes.

Four Corners journeys to the Arctic Circle to explore how the melt is challenging human understanding of global warming. The Four Corners team* joins scientists on board a Canadian icebreaker, Louis S St Laurent, as they scout for icebergs, bears and evidence of a changing seascape. Across the scientific community there is a quest for answers: How fast is the melt happening? Is it stoppable? What may be lost? What riches will be unlocked? How much global warming is caused by people and how much by nature?