here
A record low summer sea ice cover has been recorded this year and by a substantial margin. Causes can be debated, but whatever the cause this is worrying and could have a profound impact on our climate. Some have theorised that the displaced jet stream this summer has been caused by the temperature differential between the pole and the equator changing.
One of the problem with the sea ice melting is that it is a self accelerating process, the more it melts, the less reflective that part of the globe is and the more it warms.
There are also concerns that not only does it effect the jet stream but it could also affect the oceans currents, thus further impacting on weather systems.
Some Canadian scientists have predicted that the record melt this year will create a severe winter for Europe according to the guardian. I've yet to find the source for that information.