Is Glbal Warming going to make the ocean level rise 20 feet within the next 50 years?

Question

The claim is that Global Warming is melting the Antarctic glaciers and when 2 of the largest break off, it could easily raise the ocean level 20 feet. If that happens, the coasts flood, and MILLIONS across the globe move inland. Is this going to happen?

Answer 1

Research it for yourself. How many cubic feet of water are in those ice floes? What's the surface area of the world's oceans in square feet?
Cubic feet of water in ice floes
divided by
Surface area of world's oceans in feet
roughly equals
sea level rise in feet

Answer 2

Let's see if I can put it into perspective...

A lot of the Antractic periphery is experiencing some melting but there are some parts which are expanding, overall there's a net loss of ice. The Antarctic interior is extremely cold and no melting will occur here for a very long time yet.

Much of the Arctic is melting and it's melting faster than was previously thought possible. Latest observations show that if the current trend continues there will be no Arctic ice left in 40 years time.

The other major ice sheet is Greenland and this is also melting around the edges but not from the interior.

I'm guessing that when you refer to the Antarctic glaciers it's the sea ice that you mean. In recent years there have been some massive sections of the ice pack that have broken off, the largest being the Larsen B ice shelf.

Any ice which is floating does not contrinute to sea level rises when it melts, the reason being that it is already displacing it's own mass of sea water. The Arctic is floating and so too are the Antarctic ice sheets. These could melt completely and there would be no change in sea levels.

There is melting occuring from the land based ice mass in Greenland and Antarctica and this is adding new water to the seas and oceans causing them to rise. At the same time the higher average global temperatures are slowly (very slowly) warming the seas and oceans causing them to expand and subsequently causing sea levels to rise.

Currently sea levels are rising by an average of 3mm (one eighth of an inch) a year, in some places the rise is higher and is up to 30mm (one and a quarter inches) a year. This is expected to double by 2050.

Using interpolation we can calculate that sea levels should rise by 225mm (9 inches) during the next 50 years. Whilst this will lead to flooding in some places and increase the poossibility of flooding in others it won't have the devastating impact that is sometimes shown by the media. Sea level rises will be very slow and people will have plenty of time to evacuate to higher ground.

Several island communities have already been affected, the big problems will start occuring when the deltas of some of India's and Bangladesh's major rivers start to flood. Up to 60 million people live in these areas and a small sea level rise will displace them.

Answer 3

If that happens, the so-called "skeptics" will probably claim the liberals are lying wnen they say the ocean levels used to be lower! :)

Serioulsly--that level of a sea level rise, even by the end of the 21st century, is very unlikely. Estimates based on current and projected ratees of melting put the figure at around 3-8 feet.

But that's still a lot--enough to cause major coastal flooding. And yes--if the problem of climate change continues to be ignored as the Bush administration--and others, including China--are doing, such flooding will happen.

Locallly its not a major problem--in the sense that with some expence, a city could be protected by levees and, since the process wouldn't happen overnight, other areas could be graduallly evacuated.

But that's if it were a local phenomenon. We're talking about EVERY low-lying coastal area over the entire globe. That's not millions of people--its hundreds of millions. The cost would be staggering. And much of that land is hi-production agriculturalland--a serious loss to the food supply in dozens of countries. Further, the collateral effects (which are lumpted together under the term "climate change") would be devastating. Shifts like that will alter weather patterns--and even more of our food production globally is keyed to those weather patterns. All of the crucial oceanfront ecosystems would be disrupted--and in a domino effect, most other ecosystems in the world--which will have enormous--and largely unpleasant--consequences for us. We could well lose most of the food we get from the sea.

You'll notice that the word "food" keeps coming up. Think about it. How much of our foood production--worldwide--depends on the weather? If that changes--if key farmland is underwater or transformed into desert--all of this on a worldwide basis--we have a major problem. And look at history--1500 years ago Europe was invaded and conquered by peoples from Central Asia, destroying classical civilazation. Those invaders weren't looking for booty (well, they were, but that's not the main reason they invaded). Droughts and climate shifts (minor ones, compared to what we're facing) disruped ther food supply--they invade Europe in large part because of shortfalls in food production.

Not a very comforting scenario.

Answer 4

A couple of concepts:

It takes about 80 times more energy to melt ice than to heat the same amount of water one degree Celsius. In other words, when you, hear about mechanisms that are causing a degree of sea temperature increase, it'll take 80 times more energy to melt that ice.

If global temperatures are increasing, then so is the atmosphere's capacity to hold water both in the form of water vapor and clouds. You can't simply take the mass of the Greenland or Antarctic ice sheets and calculate the volume of water that oceans will rise. You have to subtract the amount of water that evaporates . And you can't simply say that all of it will come down in the form of rain. Either the Earth will be warmer or it won't, you can't have it both ways. You can argue that the rain will actually result in LESS water in the oceans, since the net movement will lead to rainwater trapped on land, especially if there is as much global drought as predicted.

Answer 5

Global Warming will only raise sea levels 20 feet if some bright engineer takes the trouble to carve Mt Everest down to sea level and use the material removed from the mountain to fill the Marianas Trench.

The majority of the ice at both poles is FLOATING. When you melt ice that is floating, the water level does not change.

You can verify that... 1/2 fill a large bowl with water. Add as much ice as you want as long as the ice floats. Mark the water level. Wait for the ice to melt. Note the water level.

Global Warming Alarmists need new lead liners in their tin hats.

Answer 6

Global warming is not what is melting the ice. The ice is melting because of the earth position to the sun at this time and the way heat is being transferred in the atmosphere. The glaciers have melted before and reformed several times. This is a process that occurs with or without humans on the planet. the global warming theory is not seeing the big picture. If science turned there heads in the right direction we could most likely predict intense weather patterns and move out the way of major destruction.

Answer 7

Good question
It could happen if steps aren't taken to stop it.
I have posted a lot of information on this site in the past about the effects of global warming.
To stop the melting of the ice caps we have to start right now by changing the way we live that contributes to global warming.
Start campaigning against the use of black asphalt. This is a major player in global warming. Check the EPA site for details.
Use light colors on rooftops, homes and everywhere else where possible.
Plant more trees, shrubs and flowers to absorb the carbon dioxide to get fresh oxygen.
Demand that Congress and other international governments mandate the use of 'clean' burning fuel in manufacturing and motor vehicles.
Stop the polluting of waterways and the oceans. The ocean floors should be cleaned up from debris that is non-biodegradable. There is plenty of open land to put the stuff and bury it.
I can go on and on. I think you get the picture.

Answer 8

The idea that large chucks of ice will raise the sea level is not quite correct, ice floats. The danger is that when the ice floats into warmer waters, it melts.

Ice Ages come and go, the coast is submerged, then is exposed. This process takes millions of years, and we are overdue-no one can tell when, but it WILL happen. We don`t need to accelerate the process


I just love that "little to no warming in Antarctica"-turn on your tv.

No, not to Fox.

Answer 9

as much as i'd like to have witty responses to all the nay-sayers in this post, i'll get right to the point:

it very well could if we don't do anything to stop it...

if u see any videos of those enormous chunks of ice falling to the ocean, you can imagine would kind of damage it can cause. the poles are not chunks of ice floating, btw... there is land under a lot of that ice, and not all the ice is simply floating. remember that this also means that penguins and polar bears are losing their land everyday...

Answer 10

Not likely. It depends on how the "feedback mechanisms" will work, and nobody knows that.

Positive feedback makes things happen faster. Like Greenland ice melts, exposing dark land, and warming happens faster.

Negative feedback slows things down. Like warmer oceans make more snow, which reflects more sunlight, and warming slows down.

Most scientists think positive feedbacks will dominate. But there is no good data, and so the very conservative IPCC report doesn't include feedback mechanisms.

http://ipcc-wg1.ucar.edu/wg1/wg1-report.html

summary at:

http://www.ipcc.ch/SPM2feb07.pdf