Environment Canada has chosen the Vanishing Ice at the Top of the World as its biggest weather story of 2007.
This Radarsat-1 image shows that in September Parry Channel was free of ice from almost one end to the other for the first time in recorded history.
Enviroment Canada say that there was "23 per cent less sea ice than the previous record of 5.3 million square km in 2005. It was as if an ice chunk the size of Ontario had disappeared in one year. Since 1971, and particularly since 1990, sea ice in the Arctic Ocean has been decreasing significantly on a hemispherical scale. But this year’s “big melt” was a shocker."
Until recently, climate scientists were not envisaging this sort of ice loss for another 30 years.