This week's Time magazine tells me that for the first time in recorded history the Northwest Passage is ice free.
The upside is that there could be dramatic reduction in shipping distances, the downside is the polar ice is melting much faster than some scientist's predicted.
Ice reflects sunlight, water stores heat from the sun - as the ice melts there is a feedback loop that increases the stored heat and therefore the rate at which the ice melts.
Ice melts opening up Northwest Passage - Telegraph
The Associated Press: Arctic Ice Melt Opens Northwest Passage
