Melting ice could cause gravity shift
Northern hemisphere sea levels 'will rise the most' if Antarctic sheet disintegrates
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Independent Minds
AFP
The disintegration of the Antarctic ice sheet could cause catastrophic flooding on the east and west coasts of America
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The melting of one of the world's largest ice sheets would alter the Earth's field of gravity and even its rotation in space so much that it would cause sea levels along some coasts to rise faster than the global average, scientists said yesterday.
The rise in sea levels would be highest on the west and east coasts of North America where increases of 25 per cent more than the global average would cause catastrophic flooding in cities such as New York, Washington DC and San Francisco.
A study into how the West Antarctic Ice Sheet could respond to global warming has found its disintegration would change the focus of the planet's gravitational field, so sea levels would rise disproportionately more around North America than in other parts of the world. If the ice sheet covering West Antarctica disappears, the loss of so much mass from the southern hemisphere would effectively make the pull of gravity stronger in the northern hemisphere, affecting the spin of the Earth and causing sea levels to rise higher here than in the south, where the mass of ice is currently located.
However, the scientists also estimated that the global average sea level would not rise as much as previously expected due to the ice sheet melting into the oceans.
This is because parts of the ice sheet are more stable than previously thought, and so would probably not slip into the sea even in a warmer world caused by man-made emissions of greenhouse gases, they found.
The West Antarctic Ice Sheet – one of the three great ice sheets of the world – is often referred to as the "sleeping giant" because it is believed to be inherently unstable, given much of its base rests on rock that is below sea level. This is thought to make it vulnerable to melting and relatively rapid disintegration, said Professor Jonathan Bamber of Bristol University.
"Unlike the world's other major ice sheets – the East Antarctic Ice Sheet and the Greenland – the West Antarctic Ice Sheet is the only one with such an unstable configuration," Professor Bamber said.
"There's a vast body of research that's looked at the likelihood of an ice sheet collapse and what implications such a catastrophic event would have for the globe. But all of these studies have assumed a five- or six-metre [16ft to 20ft] contribution to sea level rise. Our calculations show those estimates are much too large, even on a 1,000-year timescale," he said.
A better approximation, according to a study published in the journal Science, is that the ice sheet would contribute about 11 feet (3.3 metres) to the global average sea level.
However, it is not known how fast the ice sheet might disappear if global temperatures continue to rise, although many scientists believe this would take at least 500 or even 1,000 years.
"The pattern of sea level rise is independent of how fast or how much of the ice sheet collapses. Even if it contributed only a metre of sea level rise over many years, sea levels along North America's shorelines would still increase 25 per cent more than the global average," said Professor Bamber.
With less mass at the South Pole, and more water in the oceans, the Earth's gravity field would weaken in the southern hemisphere and strengthen in the northern hemisphere, causing water to pile up in the northern oceans, Professor Bamber said.
This redistribution of mass would also affect the Earth's rotation, which in turn would cause water to build up along the North American continent and in the Indian Ocean, Professor Bamber added.
Why the sea isn't as flat as you think
* Sea levels around the world vary widely on a daily basis because of tides caused by the gravitational influence of the Moon. They also vary from one region to another because of the variations in the Earth's field of gravity, and the spin of the planet of its axis of rotation.
* Global average sea levels can vary over time because of the thermal expansion of the sea caused by global warming, as well as the effect of rising sea levels caused by melting ice sheets and glaciers. Local sea levels can also be affected by land sinking or rising. Land sinking is partly responsible for causing sea levels in the south east of England to rise.
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Comments
The Telegraph should be printing balanced reports not pandering to the global warning lobby
"The comparison reveals insignificant changes at the ocean surface and at intermediate depths. But there is a significant, though small, warming trend in the deepest waters of the North Pacific."
http://www.nature.com/nature/links/0402
Besides which, on average the oceans have been cooling for the past five years, which I suspect is about to be reflected in much more severe winters.
What is the point of publishing this alarmist drivel? Are we all to become petrified of floating off into space or is this obscure publicity for Pixar's latest film. If you are familiar with the boy who kept crying "Wolf!" you might begin to understand how little impact this sort of article has.
"even in a warmer world caused by man-made emissions of greenhouse gases"
Where would that be, as the latest NASA report confirms it's not happening here?
I know you think that 'scare' stories are good for scaring the public into doing something about global warming. But, in fact the result will be a 'cry wolf' effect with the public ultimately losing faith in scientists and the arguments for protecting the environment (ie. those that are factual, and not just populist speculation).
http://wattsupwiththat.com/2009/04/17/t
http://wattsupwiththat.com/2009/05/08/g
The Force is proportional to the product of the two masses and inversley proportional to the square of the distance beween the two masses.
This story is so biased Mr Conor should try for a job at the BBC.
A quick Google of 'WAIS' also reveals an article on the NERC site which, like the Beeb's, predicts a sea-level rise of 1.5 metres: http://nora.nerc.ac.uk/769/
However, a 'mere' rise of 1.5 metres would make life a bit wet in coastal cities.
Boats rather than gas guzzlers would be the order of the day, and groundfloor carpets would be, er, sodden.
Gardens would be strictly of the water variety, so you could keep you own fish stocks, which might just be a good idea since, if you expect to be knocking around in 2050, fish stocks - like oil - will be heading south. Deep south.
But that's more alarmist drivel, of course.
Glad I won't be around to see it. Sorry for all today's toddlers; it won't be their fault!
How many other scientific theories besides climate change do you strange people deny? Are you the same people who deny evolution? Gravity? Gravity definitely doesn't exist. Alarmist drivel designed to make me scared of falling over. Must be. My dad said so.
The source of my information IS the scientific studies you refer to. The IPCC AR4 (4th Assessment Report), representing THE "scientific concensus" says in its Summary For Policymakers:
"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations."
Now go through the supporting reports (Scientific Basis, etc) in as much detail as you can manage, and try to find the evidence that supports this opinion. For that is what it is, an opinion. And not one written by the scientists, but rather by the policymakers themselves. It is a reasonable judgement and opinion, that any scientist is entitied to hold. But do not claim this oponion reflects a proof or that 'the science is settled'. The fact that millions die each year from poor drinking water - that is 'settled'.
It is also a red-herring to compare the shoddy 'science' of global warming with the excellent science that supports the existence of gravity, evolution, etc. And no, its not a "swindle". Its driven by bandwaggons, the 'end of the world is nigh' syndrome, grant applications, politics, and the fact that for 'climate scientists', their subject is now 'sexy', and will only remain so, so long as 'climate change' is the biggest threat facing mankind.
Anything to avoid the truth that we might be part of a problem and any cost to avoid facing the difficult, grown-up, pain of responsibility I suppose.
And what political motivation would there be for 'alarmist drivel'? Like risk and instability is a good thing?
The human legacy, humanities only home and we treat it like a big waste bin.
We have some sick and twisted human beings in this world, people like ex President Bush that all but said he will not try to save our world because it will cut into their big corporations profit margins.
We destroy our forests so you can have an exotic hardwoods coffee table, where are your values people?
We destroy ecosystems, animal habitats that can never be replaced, why, so some oil company, can make billions of dollars, and we can drive around in our cars and pollute the world.
Dumping radiation and medical toxins into the ocean, you think that makes the fish taste better.
Blowing the tops off the mountain's, letting minds dump their waste into Rivers, hiding deforestation, drive off the road in Oregon and it looks like nuclear weapons when off the forest is so devastated.
Willing to overfish the oceans until there's not one fish left, what are you going to eat the then?
Living in the consumer world is going to destroy our planet and the Americans are leading the way. They use 50% of the world's energy but yet they have no intention whatsoever of reducing that amount what do you think the outcome will be?
Are these sick and twisted values going to change, or are we going to end up a charcoal briquette circling the sun.
The world needs a value change.
Information like this relies too strongly on the Al Gore 'what if' approach, while failing to provide sufficient amounts of evidence to come to a well-informed conclusion.
This article can hardly be labeled scaremongering, the timescales mentioned are several hundred years. It simply asks the question, since global temperatures are rising (and for you denialists, lets just say for 'some reason') and this may cause the collapse of the most unstable ice sheet, what global effects could occur in the aftermath. This is very interesting.
Its hardly alarmist to suggest that sea level rises will be less than previously thought, did you denialists even read the article? Probably just to 'trigger happy' with your usual 'spit the dummy' routines. Sums it up really.
- Global Temperatures are not rising since 1997 (they are flat or slightly declining - probably for a few decades before rising again)
- None of the IPCC Models predicted this, to my knowledge, so we ought to be a little more sceptical about those who use these Models to predict Sea Levels (with or without Gravity effects).
Perhaps you are one of the "spit the dummy" crowd who believe that "the debate is over"?
Scientists have known what causes gravity since Einstein. Gravity is an effect of the curvature of spacetime by the presence of a mass.
You need to do some remedial science classes or something. Your education seems to be lacking.
Over the past few years some economists had been predicting a financial sector collapse with all the consequences we are now experiencing. Although they were pretty sure about the likely chain of events it was difficult to pin the timing down. Some of them, inevitably, called it too early.
Wishful thinkers in 2006 and 2007 were happily dismissing these economists because as far as they were concerned the markets were rising and the banks were still making tons of money (and presumably would continue to do so for ever and ever....).
Similarly global warming deniers are pointing to this or that statistic that shows the earth is getting cooler or the sun's activty is getting more intense, or any other statistic that gives them comfort.
Climate science, like economics, is neither exact, nor linear, but does obey some fundamental rules that allow us to make good educated guesses about the future. Overexcited deniers could calm down and at least contemplate that global warming is a real possibility.
Since I think that AGW is possible and carbon fuel sources are depleting, I suggest a massive Fission Power programme as a stopgap until we can prove Fusion and other renewable technologies at industrial scale. Strange thing is that those most convinced of AGW (usually for Political/Philosophical rather than Scientific reasons) are also the first to start screaming "No to Nuclear" when I suggest this.
Enjoy your ignorance - they do say it is bliss.
Something tells me that the ice is where it is because of gravity. And even if it melted, it would only flow with the ocean currents, and not add any weight or mass to any place on the entire planet. This will not cause any change to our gravity.
I was born in the dark, but it wasn't last night.
You know those things we call tides? They are a result of gravitational influences and have nothing to do with "ocean currents". These lumps of water that are being pulled to the moon not only cause the tides, but they actually slow the rotation of our planet. This is NOT even REMOTELY in dispute. Thus, large masses of water can indeed affect both the gravitational field of the planet and its rotation.
Your ignorance is astounding.
Well golly, I should change my mind then!