Feedbacks in the Arctic
As emissions keep rising, the Gulf Stream will carry ever warmer water into the Arctic Ocean, resulting in greater melting of the sea ice and associated albedo changes that in turn accelerate warming in the Arctic.
As the temperature difference between the Arctic and the equator decreases, the jet stream gets more elongated, at times moving all across the Arctic Ocean. This is another one of a multitude of feedbacks that contribute to accelerating warming of the Arctic Ocean.
Another one of such feedbacks is that warmer water off the coast of North America will result in stronger winds moving over the North Atlantic toward the Arctic Ocean. This can also speed up ocean currents, so it can result in more heat being carried toward the Arctic Ocean both in the atmosphere and the water.
In addition, precipitation (rain, snow, hail, fog, etc.) can be important. Precipitation can further contribute to expansion of the cold freshwater lid over the North Atlantic that prevents heat transfer to the atmosphere from water on its way to the Arctic Ocean.
Such feedbacks can dramatically accelerate warming of Arctic Ocean, resulting in heat destabilizing sediments that can contain huge amounts of methane.