This is settled. Even if the ice at the South Pole melts, and the ice on Greenland melt, there will be no appreciable change in the shoreline. Anyone who thinks otherwise is wrong.
Here is why.

Water has volume. That is what has certain groups so upset. The argument that water will take up more room than the ice it came from has already been debunked. But lets take the ice that is not floating. See. No tricks.
If ice that is not floating melts, water will run into the oceans. Because it is a fluid, the extra water will be distributed more or less evenly over the 70 percent of the earth's surface that is not land.


Still with me?
Water also has mass. And that is what the alarmists are missing. Or ignoring.
Water has a mass of one gram per cubic centimeter. That does not sound like much, does it. But consider this. A liter of water is one thousand times heavier. We are now talking about a KILOGRAM!!! Think of it. That is more than two pounds.
The elegant part of this analysis is that it does not matter how much, or little, ice melts and runs into the sea. Three things happen in ALL CASES.
First, the land under the ice starts to rise. Parts of Canada and the USA are still rising from when the last glaciers left. NEWS ITEMWho knows how long, and how high, they will rise. Same thing with Greenland if its ice melts. It will come popping right up out of the mantle like a cork. Likewise Antarctica. Only more so because - - more ice.
Second. The mass (for those of you unschooled in these things, just think weight. It means pretty much the same thing in this context.) of the oceans will go up.
Now, you are saying, we got him!!!
WRONG. For item number Three reveals all.
The third thing that will happen is that the bottom of the oceans will be pushed back down into the molten mantle. It will be pushed with a force EXACTLY proportionate to the MASS of NEW WATER. That is why "the amount don't count." And not only will the basaltic ocean pans be pushed down, because the planet is not going to get smaller, something has to give. And here is where the most stunning realization comes in. The continents, and continental shelves, are going to be pushed up. Just like puss from a squeezed boil.
So. No change in the shore line. We might even get more land, instead of less. You can run the numbers if you want. I did. This is irrefutable. For example, the most important number is the difference between the specific gravity (that means density for those of you who slept during science class) of granite -2.75 or 2.8 because it is a felsic rock - and water. The specific gravity of water is 1. Of course this is true only at 4 degrees C. So, we have water, which is only one third as specific as granite, added to the ocean over the basalt. But because the oceans cover about 73% of the surface of the earth, to an average depth of 12,200 feet, the water will push down harder than the continents will by a ratio of approximately 7 to 3. It does my faith in GAIA good to see how close this ratio comes to balancing out the specific gravity difference between the water and the granite.
BUT NOT QUITE. The result, as you may by now really believe, is that the ocean floors will go down and the continents will go up. AND "The amount Don't Count!"
It is already happening. The Solomon Islands are now 15 feet higher above sea level than they were two months ago. They had an earthquake. REEF EXPOSED

Well, no one said it would all happen quietly in the middle of your nap, did they??? It is just the beginning.