These shocking satellite images from the European Space Agency show how the Arctic summer ice pack has changed in just one year. The left image was taken in August 2005 - the right in August 2006. See the difference?
In both images, pink represents pack ice and the colour blue open water. Intermediate colours orange, yellow, and green indicate lower ice concentrations of 70%, 50% and 30%, respectively. In the 2006 image, the low concentration ice pack can seen by the high concentration of yellow, orange and green colours.
By the way - the UK and Ireland haven't somehow drifted north - the ESA folks just added the outlines to give a sense of scale.
Over the last 25 years, satellites have been observing the Arctic witnessing reductions in the minimum ice extent - that is, the lowest amount of ice that occurs, and the end of the summer. This minimum ice has shrunk from 8 million km² in the early 1980s to the historic minimum of less than 5.5 million km² in 2005, changes widely viewed as a consequence of greenhouse warming.
The reason behind the reduction in the 2006 photographs is still unknown - but stormy conditions may have been a factor.
Mark Drinkwater of ESA’s Oceans/Ice Unit said: “This situation is unlike anything observed in previous record low ice seasons. It is highly imaginable that a ship could have passed from Spitzbergen or Northern Siberia through what is normally pack ice to reach the North Pole without difficulty.
"If this anomaly trend continues, the North-East Passage or ‘Northern Sea Route’ between Europe and Asia will be open over longer intervals of time, and it is conceivable we might see attempts at sailing around the world directly across the summer Arctic Ocean within the next 10-20 years."
ESA: Arctic summer ice anomaly shocks scientists »
ESA: View the photographs»
Further reading:
Stop climate change »
Wikipedia: The Gulf Stream »
Wikipedia: Thermohaline circulation »