But I was referring to the purely physical effect of the displacement of fluid by a floating solid. You clearly understand this, but let me expand on it for the benefit of those who may not.

Fill a glass of water to the brim and then place an ice cube in it. Excess water will spill over the edge of the glass until the cube floats in a glass filled to the very top. However, as that cube melts, no more water will spill out, because the volume taken up by the cube as it melts is identical to the volume of water displaced by the submerged ice when it is frozen.

All the sea ice at the poles is only a few feet thick, and it floats on water, so its melting will add no water to the ocean basins. It is all the ice on land, mostly in Greenland and Antarctica, that has the potential of flooding the coastal plains where the majority of the earth's people live.

The major factor, as you point out, is albedo. When the sea ice melts in summer, sunlight striking the poles is not reflected back into space, it penetrates the sea and warms it up. As the ice melt increases every summer, the polar seas warm up making it harder for them to freeze up the following winter. What we are seeing now is an acceleration of the process because snow is not falling on existing sea ice, making more and more ice pack. It is falling into the water. More and more of the ice we are seeing is "new ice", ice that formed in the most recent winter, as opposed to multi-year ice which has been growing steadily thicker due to freezing below and snow above. New ice is thinner, and more easily broken up and scattered by wave and wind. Although its albedo properties are just as effective as old ice, its thickness and durability is not.

This is why the melting, as noted in those graphs I reproduced, is not just getting worse, its getting worse faster. The winter ice levels are still pretty high (although somewhat lower every year), but the summer ice is disappearing at an alarming rate. I believe it is now vanishing at a rate that will give us our first ice-free summer in the very near future.

Continental ice, however, is thousands of feet thick in Greenland, and miles thick in Antarctica. The continental melting that could flood large coastal areas, if it ever comes, will only become noticeable after the world undergoes dramatic climate shifts in the temperate zones.

Our descendants won't burn up, or drown, they'll starve first.