Quote Originally Posted by Stig
Why is does Northern Europe have such a good climate, compared to Canada which is at the same latitude?
We have a good gulfstream.
What will happen to that gulfstream if the ice melts?
It will disappear.
What consequences does that have?
It gets colder.
How much?
Well you can call it an ice age, as it will be the Younger Dryas all over again.
It's been said that the effects of the "conveyor" have been much over-stated.

Here's an article from the "American Scientist" for your enjoyment.

The Source of Europe's Mild Climate: The notion that the Gulf Stream is responsible for keeping Europe anomalously warm turns out to be a myth

The Gulf Stream indeed contributes to Europe's warmth, but it is wrong to conflate the climate difference across the North Atlantic with the northward flow of warm water in the Gulf Stream. This erroneous logic leads to such statements as (from The Times of London): "The British Isles lie on the same latitude as Labrador on the East Coast of Canada, and are protected from a similarly icy climate by the Atlantic conveyor belt." Such claims are absolutely wrong.