[ukmicky (OP)]

Greenland has had many periods through history where its climate  has been much hotter than today, rubbishing the idea as far as i'm concerned that through global warming we are melting the glaciers more than ever before.

When the vikings first colonised it, it was green and temperate ,and for a couple of decades after the 1920s its climate was actually warmer than it is today.

But even though greenland is colder now than it was in the 1920's the environmentalists are still saying that we are through global warming causing the glaciers to melt and slide into the sea and they say that the speed at which they are sliding has  increased over the last 5 years.I agree their movement towards the sea has speeded up but what could be fueling this increase.

Melted ice can act as a lubricant allowing the glaciers to slide and they believe that global warming is the cause for the melting water, but could it be something else.


Could the cause of the glaciers sliding into the sea be due to the glaciers themselves.

1.
Could the lower regions of the glaciers be comprised of a form of ice which is weak and can't handle the mass of the glacier above it, giving way and causing the glacier to slip. Are there different types of ice with diferent stengths and properties

2
Or if the glaciers got to big and heavy can their own weight and stored up energy  due to then being on a slope cause the bottom region of the glacier to heat up and melt lubricating and speeding up there natural movement towards the sea.

3
Are their any volcano's under greenland which could cause the ice to melt or does greenland suffer from minor earthquakes

Michael

[neilep]

As a firm believer in empirical study I will take two ice cubes and place them atop a fish finger each at an angle of 33 degrees. Every so often I will light a match under one of the fish fingers to represent a volcanic eruption. I will paint the fish fingers green to symbolize Greenland.

I am sure over time, perhaps a year or two, I will be able to report back what should be irrefutable data on the phenomena.

Men are the same as women, just inside out !

[VAlibrarian]

Dear Sir:
As one of those global warming blokes, I will firstly admit that this is a tricky topic. Most of those discussing it have made up their minds already, me and Al Gore for example. However it is important to preserve science as a value in this discourse, because science is in fact the origin of the global warming theory.

The central argument of the human activities-induced global warming crowd is that global warming from increased atmospheric CO2 must be a cumulative phenomenon. Thus my crowd offers relatively small increases in global temperatures of perhaps one degree over the past century as proof that the future is likely to hold far steeper increases of several degrees in the next century or so. This will inevitably be unconvincing to those insisting that we need to see the 3 or 4 degree increase before we take the whole thing seriously.

It is a mindset thing. I have no problem imagining that the thousand barrels of petroleum burned every second by the human race is sufficient cause for sliding glaciers. 99% of atmospheric scientists have no problem imagining that connection either. Could they be wrong?
It is not impossible, but I see no point in imagining that they are making it up through wrong headedness or self interest.  

I did find out this morning that I have been guilty of some exageration regarding global warming. USA Today newspaper showed a map of future flooding resulting from global warming and it is clear that it will take several centuries for the bottom third of Florida to go under water, rather than the 100 years that I have been quoting for the entire State to go under water. Sorry!

chris wiegard

[VAlibrarian]

On the other hand it was pretty clear that all of Louisiana south of New Orleans will be gone in a century, so maybe they shouldn't replace those houses that Hurricane Katrina ruined.

chris wiegard

[ukmicky (OP)]

Michael


FORGETTING ABOUT MY QUESTIONS FOR NOW.


We are not the cause of global warming its part of the natural cycle of the earth, you know that ,I know that  but if you listen to the global warming brigade their statements always fail to recognise that fact. All there news reports aimed at the general public are always worded to make everybody believe that global warming is a phenomenon which is happening solely due to human activities.

I personally dont believe we are having much effect on Global warming, I don’t believe the earth is quite as fragile as they try to make out. The environmentalists are doing what they do best, making up rubbish to scare people in order to gain money and position and the governments of the world are doing what they do best, giving in to the crackpots in order to get their votes. (PS  I’m not saying you’re a crackpot)[]

The fact that the environmentalists are using Greenland as a major part of their evidence and by saying we are causing its climate to warm up melting the glaciers shows shows how much they are prepared to lie, because records show its just something which happens to Greenland from time to time and shows that their statements on global warming are not as scientifically proven as they are trying to make out.

They've got Greenland wrong, and I believe they know they are wrong but Greenland has such potential as a scare tactic in persuading  people to come around to there thinking that it’s worthwhile for them to lie. And if they lie about that what other lies will they tell.

Most of the global warming brigade are greenpeace, anti nuclear power activists the type of person who reject anything which isnt green and would prefer the world to go back to the natural non technical world of 200 years ago.


Michael

[JimBob]

quote:Originally posted by ukmicky



(snip)

1.
Could the lower regions of the glaciers be comprised of a form of ice which is weak and can't handle the mass of the glacier above it, giving way and causing the glacier to slip. Are there different types of ice with diferent stengths and properties

2
Or if the glaciers got to big and heavy can their own weight and stored up energy  due to then being on a slope cause the bottom region of the glacier to heat up and melt lubricating and speeding up there natural movement towards the sea.

3
Are their any volcano's under greenland which could cause the ice to melt or does greenland suffer from minor earthquakes

Michael

1 and 2 are the same question as ice uinder pressure has different properties under pressure. The crystal structure becomes more elastic and some crystaline structureal changes occur. Melting does occur if the pressur becomes high enough..

Volcanos are not a big problem. Say a volcano is 20 square miles. The Greenland Ice sheet is over 7x10^6 square miles. A volcano is very small compared to the arieal extent of the sheet. There are also no known or even suspected fissure eruptions, such as those cutting through Iceland and extending under the sea to the north and the south.

However, I will not depend on what I was taught. I will wait for Neil and the fish finger study.

GLOBAL WARMING - This deserves a thread of its own. I think I will start one now.



The mind is like a parachute. It works best when open.  -- A. Einstein

[ukmicky (OP)]

Cheers JIM

So it is possible under certain circumstances for the glaciers on Greenland to be the cause of there own demise.
In other words if a glacier was tall enough then the pressure at the base could cause it to melt, and the resulting melt water  could then  lubricate and hasten their journey into the sea.


So now i need to do some research and find out how much ice is contained in the average greenland glacier.




Michael

[JimBob]

Michael, I think you are beginning to understand how a glacier - all glaciers - move. Isn't science fun?

[]

The mind is like a parachute. It works best when open.  -- A. Einstein

[neilep]

Day three of my empirical research.

No change, despite one ice cube being subjected to two volcanic eruptions.

Wifey is unhappy about the ash and smoke in the freezer and I don't know why.
I've tried to explain to her that it's in the name of science and that as Jimmy Boy has said, 'science is fun '...so why is she not enjoying it ?
I've tried to get her to see reason that this experiment will only last a year or two !....Sheeesh !!...women eh ?


Men are the same as women, just inside out !

[JimBob]

Neil,

Try to placate wifey. A valued researcher is no good to sciene in the hospital wraped in bandages with tubes in every orifice.

Michael,

Look also at the shape of the island of Greenland. It is bowl shaped so it take other mechanisms besideds melting at the bottom to cause the glaciers to shrink.



The mind is like a parachute. It works best when open.  -- A. Einstein

[ukmicky (OP)]

I'M PLOUGHING THROUGH LOADS OF WEB PAGES []

Michael

[VAlibrarian]

If I am a crackpot, I am not of the anti-nuke variety. On the contrary, most of those who seriously consider human activities responsible for the observed rise in temperature are very much in favor of nuclear power. Nuclear power produces no CO2. If we wish to address the atmospheric CO2 problem (those of us who consider it a problem)it is obvious that we have to get energy from somewhere or no longer have cooked dinners. As I much prefer cooked meat to the raw stuff, but am quite convinced that our CO2 contributions to the atmosphere will come back to haunt our grandkids, I have no choice but to favor the expansion of nuclear power to take up the slack that would result from reducing use of coal and petroleum.
Actually my viewpoint is that those who deny the observed reality of global warming or seek to blame it on some other mysterious chemical process rather than atmospheric CO2 increases are the true crackpots. But as I say, viewpoints.  My belief is that public opinion will gradually catch up to the 99% of atmospheric scientists who share my view. Yours is that the scientists will eventually catch up to the general public.  Could be, but how often does that happen?

chris wiegard

[another_someone]

quote:Originally posted by VAlibrarian

If I am a crackpot, I am not of the anti-nuke variety. On the contrary, most of those who seriously consider human activities responsible for the observed rise in temperature are very much in favor of nuclear power. Nuclear power produces no CO2. If we wish to address the atmospheric CO2 problem (those of us who consider it a problem)it is obvious that we have to get energy from somewhere or no longer have cooked dinners. As I much prefer cooked meat to the raw stuff, but am quite convinced that our CO2 contributions to the atmosphere will come back to haunt our grandkids, I have no choice but to favor the expansion of nuclear power to take up the slack that would result from reducing use of coal and petroleum.

While I am in general in favour of a healthy nuclear sector (clearly in present Iranian government also feel likewise in this matter), I would ask the following question about the implementation of the technology.

While it is true that nuclear power does not pump CO2 into the atmosphere, and for those that fear the slight increase in CO2 will significantly retain some more of the suns heat than might otherwise be, this is seen as a positive.  On the other hand,  nuclear power does generate very large amounts of heat in a direct manner, far more so than the burning of fossil fuels, and only a small amount of this heat is converted into usable power, and the vast majority of this heat is dumped directly into the atmosphere.  How does this direct dumping of heat into the atmosphere compare with the trapping of a small amount of heat that we receive from the Sun?

George

[another_someone]

quote:Originally posted by VAlibrarian
My belief is that public opinion will gradually catch up to the 99% of atmospheric scientists who share my view. Yours is that the scientists will eventually catch up to the general public.  Could be, but how often does that happen?

My own anecdotal observation is that public support for the greenhouse argument has now peaked, and beginning to decline.  Political support has yet to peak, as it tends to lag behind public opinion by some considerable time.  The scientific community is clearly highly fragmented on the issue, although it is clear that those who are best at forecasting disaster will attract the greater funding (if no disaster is pending then there is very little political imperative to throw money into the research).  I am not sufficiently in touch with academia to have any sense as to what the overall direction of belief is and was, but clearly, different specialists will have a different perspective on the matter, and will come to different conclusions.

George

[VAlibrarian]

Academia is not monolithically solid in favor of global warming, but there is a definite majority, and it appears to be growing. James E. Hansen of the USA and Tim Flannery of Australia represent the majority of scientists who are highly concerned over the eventual impact of global warming over a hundred years from now.

There are several professors of environmental studies or atmospheric science (Patrick Michaels of the University of Virginia and Richard Lindzey of MIT) who argue that the majority view is exaggerated. At first some of these argued that global temperatures are not climbing. They no longer can convincingly make that argument now, so they argue in some cases that it is not yet proved to be related to human activities. The two scientists mentioned in this paragraph have taken lucrative public speaking fees from oil and electric utility companies.

We had in this country (USA) a very influential anti-global warming lobby made up of Republican think tanks and industrial political lobbies. They spent many millions in recent years to whip up public opinion against the Kyoto accords, the concept of government imposed mileage standards for vehicles, and the idea of reducing fuel use by imposing higher taxation (as was done very succesfully in the UK.
Over the past couple years, certain industries have left this group, because they have decided that global warming is real and is caused by fuel burning and that they can no longer pretend it is not. BP will tell you that its acronym no longer stands for "British Petroleum", but rather "Beyond Petroleum". In fact, in the United States some industries like General Electric are ready to make a profit from exploring renewable energy, while Exxon and General Motors are clinging to the concept of "when you run out of gas, drill deeper".



chris wiegard

[another_someone]

quote:Originally posted by VAlibrarian
There are several professors of environmental studies or atmospheric science (Patrick Michaels of the University of Virginia and Richard Lindzey of MIT) who argue that the majority view is exaggerated. At first some of these argued that global temperatures are not climbing. They no longer can convincingly make that argument now, so they argue in some cases that it is not yet proved to be related to human activities. The two scientists mentioned in this paragraph have taken lucrative public speaking fees from oil and electric utility companies.

Are you saying that these people changed their views once the oil and electric companies started paying them, or are you suggesting they had no opinion at all until the oil and electric companies told them what to think?

That the oil and electric companies may find their opinions comforting does not of itself mean the opinion is any less genuinely held for totally honest reasons.  Ofcourse, neither that does it prove that these guys are not charlatans who simply say what it is most profitable for them to say (they would not be the first scientist to fake results to suite their funding requirements).

The trouble with arguing the global warming is a consequence of human activity is that you have to demonstrate that global warming would not be there in the absence of humans.  All the records show that climate is anything but stable, whether humans are here or not; and as I understand it,m there is not very much argument that global warming would have happened since the middle of the 17th century, with or without human action.  The only question is one of degree rather than one of whether or not.

quote:
Over the past couple years, certain industries have left this group, because they have decided that global warming is real and is caused by fuel burning and that they can no longer pretend it is not. BP will tell you that its acronym no longer stands for "British Petroleum", but rather "Beyond Petroleum". In fact, in the United States some industries like General Electric are ready to make a profit from exploring renewable energy, while Exxon and General Motors are clinging to the concept of "when you run out of gas, drill deeper".

There are two different issues you are talking about.  Firstly, the finite nature of any resource, and that it makes sense to look to the next step beyond petroleum; and the other issue is the matter of global warming.

Whether (or rather, to what extent) Exxon and GM are correct in their argument that more oil can be found by digging deeper is a totally separate issue than the one about whether one would wish to burn that oil if it were found.

Beyond that, the oil industry uses science and engineering for its own ends, but at the end of the day they are economic entities, and being right or wrong is not a technological issue, it is an economic, and that ultimately means a political issue.  BP are concerned about their public image, not about whether they are technologically right or wrong.  You just have to look at what is happening in places like Nigeria and Venezuela to see how important the political angle is for the oil industry.  If you can't keep the politics on your side, then the best science in the world will not save you.  If you can keep the politics with you, then you can always fudge the technical issues (after all, those technical issues will effect your competitors as well as yourself, so there is little to be competitively gained by arguing one climate model over another on purely scientific grounds, but pre-empting the political situation can put you in a stronger position against your competitors, but only if you get the politics right).

George

[crandles]

quote:Academia is not monolithically solid in favor of global warming, but there is a definite majority.

Oh come on, that is a massive understatement. It is more like 2000:7 and a scientific consensus doesn't get much stronger than that.

http://en.wikipedia.org/wiki/Global_warming

quote:However, the strong scientific support for man-made global warming implies that such alternative opinions are not widely held. In the journal Science, an essay by Naomi Oreskes considered the abstracts of all 928 scientific articles in the ISI citation database identified with the keyword "global climate change". Dr. Oreskes concluded that none of these abstracts attempt to refute the position that man-made emissions of greenhouse gases are a substantial contributor to recent warming.

See also
http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change
http://en.wikipedia.org/wiki/Global_warming_skeptic

[crandles]

>1 Are there different types of ice with diferent stengths and properties

There certainly are but I don't really know of any reason to think the mixtures vary so you could suddenly get ice that is on average weaker at the bottom.

>can't handle the mass of the glacier above it
This is certainly not just possible but is how a glacier moves. You should be aware that global warming theory predicts that warming leads to an increase in the hydrological cycle ie more evaporation and more precipitation. Therefore it is a prediction that glaciers get thicker and possibly melt a bit more at the end. This is what we are seeing - there is an increase in mass in central Antartica. (edit: I am also fairly sure that some parts of greenland are showing an increase in the mass balance. Clearly some areas where the glaciers are moving much faster are showing decreases.) The global warming prediction is therefore being born out. Therefore this suggestion of yours is already part of the science that supports global warming theory.

2 yes

3. I don't know. However you would have to show a change in activity to undermine the massive scientific consensus on global warming.

[ukmicky (OP)]

Hello crandles and welcome to the forum

 

quote:>1 Are there different types of ice with diferent stengths and properties

There certainly are but I don't really know of any reason to think the mixtures vary so you could suddenly get ice that is on average weaker at the bottom.

what if the layer at the bottom  was full of dust and dirt  , would or could that cause it to be weaker or even more prone to melting

Michael

[crandles]

I just don't know about whether dust and dirt at the bottom could cause weakness. However I would question the relevance:

Dust and dirt from the last 150 years would be on top of the glacier. This will make it easier to melt the top by reducing the albedo and also the melting point. However, I am not sure how much effect this has.

Since we are seeing glaciers retreat in large numbers of diverse locations (~98% of glaciers, I think), it would be very odd if it could be put down to local factors eg volcanoes.

I am not sure why you would expect a difference at the bottom eg comparing ice that formed 10,000 years ago with ice from 10,100 years ago.