Walbrook, the less ice the less reflection leading too the warming of the local oceans which leads to more melting ice ect. Its known as a positive feedback loop and there are quite a lot of them separate from this, some are carbon stores being released from permafrost, which is one of the reasons modelling can be difficult,
Sea ice obviously does not add in itself to rising oceans as it is already in the ocean, however as the sea ice decreases due to the above positive feedback loop then you obviously end up with land ice melt (which we are already seeing) this adds to the oceans rising. These positive feedback loops can lead to things accelerating out of control very quickly which we expect to see in the next couple of decades whether people deny it or not.
