Melting icebergs from global warming raises ocean level??

Question

I have a hard believing that melting icebergs would cause ocean levels to increase. floating ice displaces the same amount as water- if you fill a glass with ice and then with water to the top of the glass and let it melt, the water will not overflow. isn't melting icebergs following this same concept. If the ice melted, wouldn't this cold water lower the water temp??

Answer 1

Most icebergs and glaciers are landlocked. It isn't that they are displacing water by floating on the ocean, they're melting and the runoff that was once frozen on solid ground flows into the oceans...therefore raising the water level.

The free floating glaciers aren't the problem.

Edit: And yes, this melt water can change the temperature of the ocean currents. Cold water sinks and it could throw the natural currents all off balance and create a multitude of problems.

Answer 2

The vast majority of ice is on land. Antarctica, Greenland, glaziers in Norway, Canada, Himalayas, etc. When that ice melts and the water runs down to the oceans the ocean levels will rise. However there is an interesting opposite to this. As the warm Gulf Stream heads north along the east coast of the USA, it is loaded with salt due to evaporation of the water down near the Equator. When it gets near the north pole it gets diluted by melting ice. That changes the salinity and temperature of the Gulf Stream. It sinks and flows back down south on the west side of Europe and Africa. Then it goes across the Atlantic towards American and the whole cycle starts again. However, what happens when all the Arctic ice melts? Then the Gulf Stream goes north and does not have a change in salinity and it does not cool so much. There is one theory that the circular flow will stop. If that happens then the warm waters that make England and the Scandinavian nations warm will stop. They will undergo a cooling and perhaps even a small Ice Age. The flow will be more east and west like it is in the Pacific and we may see monsoons hitting north Africa and it may bloom again. Read up on the Little Ice Age and the Medieval Warm Period and you can see what swings of temperature can do in the North Atlantic. In the meantime, do not buy low laying ocean front property.

Answer 3

ice simply displaces more space than the same amount of liquid H2O. a given amount of water takes up more space when frozen than liquid, therefore the levels of the oceans would recede as the ice melts.

how about the frozen ice on top of a land mass like greenland? as it melts and runs off the land will rise due to it's own bouancy. the result would not cause oceans to rise.

and as the earth gets warmer due to greenhouse effect, more of the worlds H2O will be suspended as a vapor in the atmosphere, again not contributing to the net rise in the ocean levels.

this appears to be bigger in the news than real lifes of you and i.

Answer 4

As mentioned, it is the melting of LAND-BOUND ice that is causing the problem. One viewpoint?

"Since the world’s oceans occupy a surface area of 139 million square miles, it isn’t too hard to figure out how much the ocean surface would rise, if all this land-bound ice melted. There are about 1.2 million cubic miles of ice atop Greenland, and if you pour all that into the oceans (1.2M cubic miles / 139.0M square miles of ocean surface) you get a rise of .083 miles, which is 45 feet. Calculating Antarctica’s frozen ice at a volume of 7.7 million cubic miles (1.32 miles thick x 5.3 million square miles), and pouring that into the oceans (7.7M cubic miles / 139 million square miles of ocean surface) you get a rise of 292 feet."

Answer 5

Good point. However, the problem lies with all the glaciers above the water level and the ones partially supported by land masses. All those include trillions of gallons of water, and could raise the sea level. However, nothing this drastic is going to happen in our lifetime.