scientists wrong about glbal warming consequences?

Question

now just so u know i fully believe in global warming, but i have one problem with it. a bunch of studies and whatnot say that when the polar ice caps melt the water level will rise so many feet causing massive flooding. but wouldnt the water level drop? when water freezes it gets larger, so when it melts it would get smaller.

so when the polar ice caps melt wouldnt the water level lower?

are you serious? how can u not understand this. if u have an ice cube in a cup of water and it melts the volume would decrease because the ice has changed into water which has less volume.

Trevor, that last clip showed ice that wasnt even in the water. where in the hell have you ever seen a massive iceberg levetating a few feet above the water.

Answer 1

It took me a while to find an answer to this one cb- good question.

The answer involves hydrostatics, buoyancy, and isotropic pressure. Begin with the fact that ice is less dense than water at 32 F. A mass of ice will occupy 9% more volume than an equal mass of water. This is why we see 9% of an iceberg above water level.

Experiment: An ice cube floating in a glass of water that is filled entirely to the brim. When the ice cube melts, the water level will stay the same, right at the brim.

The ice cube will have to displace enough water to support its weight in order to float. The volume of this is V=m/d, where m is the mass of the ice cube, d is the density of water. When the ice melts, it turns into water. The volume of water will also equal V. Hence the water level remains the same. The catch is, we are speaking of fresh water here.

There is a difference in density between fresh water and salt water. Because freshwater is not as dense as saltwater, freshwater actually has greater volume than an equivalent weight of saltwater. Thus, when freshwater ice melts in the ocean, it contributes a greater volume of melt water than it originally displaced. Thus, if all ocean ice melted the contribution of sea level rise would equal 1.6 inches! Global warming fanatics measure in all ice (even all ice on land mass) in order to manipulate their figures to cause public alarm.

http://www.physorg.com/news5619.html

Answer 2

Most of the Antarctic ice is on hand. Despite the change in volume, having it move from being ice on land to water in the sea should raise the sea level. The North polar cap floats on top of the water, mostly below the surface. It should be expected to raise the sea level also, but not as much as the South. The North should finish melting sooner, because there is more in the South, and it is colder there.

Answer 3

The Arctic is, for want of a better description, a huge lump of floating ice and as such it is already displacing it's own mass of sea water. When it melts it will have no effect on sea levels.

The important thing is MASS, it doesn't matter how big it is or how dense it is. If for example you had a small iron boat that weighed 1000 tons and a large wooden boat of the same weight and put them to sea each would displace the same amount of water even though they're very different sizes and densities.

The same happens with ice, there is some air trapped in the ice and it's less dense than water - hence it floats (water has a unique property in that it is at it's densest at 4°C and not at it's freezing point).

Unlike the Arctic, the Antractic and Greenland ice are land based ice masses, when melting occurs here fresh water runs off into the sea causing the sea level to rise.

Here's a video similation of what happens when floating ice melts http://oceandrilling.coe.tamu.edu/curriculum/Sea_Level/Ice_Volume/floatingice.html and here's another video showing the effects of land based ice melting - http://oceandrilling.coe.tamu.edu/curriculum/Sea_Level/Ice_Volume/ice.html

Sea levels are currently rising by 3.1mm a year, just over half is caused by thermal expansion of the oceans with most of the remainder being caused by meltwater from the Arntarctic and Greenland ice sheets and ice caps (220 cubic km from Greenland last year, 82 from Antarctica).

If the whole of the Arctic melted sea levels would remain unchanged, if all the Greenland ice melted sea levels would rise by 6.55 metres, if all the Antarctic ice melted sea levels would rise by 73.42 metres. If all the ice on the planet melted sea levels would rise by 80.32 metres - something that's not going to happen for a very long time.

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EDIT: RE YOUR ADDED DETAILS

The second clip simulates what happens when land based ice melts. Land based ice is not in the water, when it melts the water forms streams and rivers that make their way to the sea. When they enter the sea they add to the water that's already there and cause the sea level to rise.

Watch the videos again. In the first one the ice is already in the water just like the Arctic ice is, when it melts there is no change to the water level. In the second clip the ice is not in the water, as in the Greenland and Antarctic ice, when it melts the water level rises.

Answer 4

Cold water has a higher density than hot water. As the water gets colder they sink to the bottom.Water has the highest density at 4 degrees Centigrade. When water turns into ice, the ice will float on top of the water ( at 4 degrees Centigrade.), When the polar ice caps melt, (solid water ,ice, turns into liquid at zero degree centigrade) the volume actually will lower a bit, however when the temperature rises to more than 4 degrees, the volume will increase, to many feet and cause flooding as the scientists say.

Answer 5

Your premise is only accurate if all the arctic/antarctic ice in the world was floating in water. It isn't. Whatever ice does not currently displace water will add to the volume of it.

I.e. if an ice cube in your glass melts, the water level doesn't change much, but if you dump more ice cubes into the water it does.

Answer 6

The reports are wrong in that political pressure forced conservative reporting. They do not include effects of the methane that will be released by the melting of the permafrost, nor the methane from the billions of tons of methane hydrate that will disassociate when the water gets warmer.
You question about ice is irrelevant because the float takes care of the expansion part.

Answer 7

Most of the water in question is well above sea level, when it melts it it going into the oceans and the sea levels will rise. The differences in volume because of temperature will be negligible, as the volume change is too small to be of any practical significance.

Answer 8

Oh gawds. Let me answer your question with another question. Can you imagine an Arctic or Antarctica that NEVER gets below 32 degrees Fahrenheit, despite the lack of sunlight for six months out of the year?

So, by your ice cube in a cup of water, sitting at room temperature rationale: If you keep adding ice cube(s) to the cup of water, the volume of water would eventually disappear by the melting action of said ice cube(s).

Answer 9

As water heats from 0 deg C, it expands. There's an awful LOT of water in the oceans!

Answer 10

The problem is land based ice, like Greenland and Antarctica. When it melts and runs into the sea....