Global Warming

[SimpleSimon]

The article quoted below will likely never see the light of day in the "popular press", for it contradicts received wisdom. It is, nevertheless, good science.


Tree Ring Study Shows Warm Earth Cycles

By PAUL RECER
.c The Associated Press

WASHINGTON (March 21) - An unusually warm period a millennium ago may have been part of a natural planetary cycle, researchers say in a study of tree rings that scrutinizes the link between human activity and climate change.

The study, appearing Friday in the journal Science, analyzed ancient tree rings from 14 sites on three continents in the northern hemisphere and concluded that temperatures in an era known as the Medieval Warm Period some 800 to 1,000 years ago closely matched the warming trend of the 20th century.

In recent years, many climate scientists have said an unprecedented warming spell that began last century and continues is caused by the Greenhouse effect. The Greenhouse effect is blamed on an increase in the atmosphere of gases, principally carbon dioxide, from the burning of fossil fuels, which trap heat just as do glass panes in a greenhouse.

The tree-ring study gives another perspective on Earth's natural cycles, said Edward Cook of the Lamont-Doherty Earth Observatory in Palisades, N.Y. Cook is co-author of the study with Jan Esper and Fritz Schweingruber of the Swiss Federal Research Institute.

Cook said the study shows the Earth to be ``capable of rapid changes and long periods of above average warmth on its own without greenhouse warming.

``We don't use this as a refutation of greenhouse warming,'' said Cook. ``But it does show that there are processes within the Earth's natural climate system that produce large changes that might be viewed as comparable to what we have seen in the 20th century.''

Cook said the study found that, based on the growth of rings in the trunks of trees that lived hundreds of years ago, the temperatures during the Medieval Warm Period were about equal to the warming trend that started in the 20th century.

``Greenhouse gases were not a factor back in the Medieval Warm Period,'' said Cook.

The Intergovernmental Panel on Climate Change, an international group, has predicted that the current warming trend will continue deep into the 21st century, with average temperatures rising by 2.5 and 10 degrees. Based on this prediction, there have been international proposals for systematic reductions in the burning of fossil fuels. The proposal has been resisted by the United States, particularly the Bush administration.

Cook said data used in the climate change panel's calculation is based on a model that compared the preindustral age climate with the climate of the 20th century. The model did not include a Medieval Warm Period. Including data from that era could change the calculations, Cook said.*

``The Medieval Warm Period is in some sense comparable up to 1990 in the 20th century,'' said Cook. ``But that does not say that the 20th century hasn't been perturbed by greenhouse gases. The real challenge is to factor out the natural variability from'' manmade causes of global warming.

Cook said the panel's temperature warming prediction could be correct. Based on the new tree-ring data, however, he said the warming could be in the lower part of the temperature range forecast by the group.

Keith Briffa and Timothy Osborn, climate scientists at the University of East Anglia in Britain, said the study by Cook and his colleagues ``provides evidence for greater climate swings in the last 1,000 years than has yet been generally accepted.''

In a commentary in Science, Briffa and Osborn said a need exists for more such independent studies to refine predictions for global warming in this century.

* - emphasis added

[MAC]

1) Joe Blow America doesn't have time in his busy day of worrying about paying for that matching pair of jet skis to sit and think about the concept of weather trends that take thousands of years to cycle or patterns that canbe measured over millions of years. the scientists are supposed to know this stuff the way his mechanic knows about his car and then they should tell him in a 15 sec blurb on the news every 28 minutes.

2) Follow the dollar.
If you are inventing a new medicine you get paid the most when it works.
If you are an attorney, you get paid the most when you win.
If you are a scientist, you get paid the most when your findings qualify you for highly federally funded research into popular studies.
Someone else did all the work to prove there's a problem all you hva e to do is find a way to support that and they will pay you to add to the "preponderance of evidence"
Why?
The people who pay for research make their money when they get to allocate MORE $$$ to try to fix the problem.
So thet take our money and give it to someone to prove theirs a problem.
Then they sell us the problem.
Then they come up with great ideas about how to spend more
money to FIX the problem (which never actually gets fixed)

[estero]

We all know its happening, however, no one does anything about it.

[TotalAnarchy]

Whether the world is getting warmer as a natural trend, the evidence DOES support that this shit we pump into the air aint helping ANYTHING.

And you cant refute the growing rate of cancer or the dying populations of algae from the radiation leaking in through that fucking big hole in the ozone layer. Not unless their instruments lie.

[squee]

Yeah, well look, TA...

First it's "Oh no, we're wrecking the environment with our pollutants...!"
But...no...in fact we're not, not in the way that people want us to think. Global warming is bullshit. Arsenic in the water supply and acid rain are not. And yet we have the Kyoto Accords cutting down on pretty much only greenhouse gases and not much else...

Now it's "Oh no, we're wrecking our health with our own pollutants...!" Poetic justice, yes, but at the same time nobody is targeting this issue...

With the Greens it is mostly about control and economics...that is why the EPA will muster a SWAT team if a farmer kills a beaver whose dam is fucking up his cropland, whereas they don't do SHIT about major corporations that are fucking us over.

Bottom line is, if you believe what you are being told, you are a tool and you deserve what you get :)

[TotalAnarchy]

The fact is, the earth is heating up, right?

And we can be pretty sure that all this shit we send up in fumes (which the U.S. produces 25% by itself) cant be helping this at all, instaid, it could be making what might be a cyclical warming into something much more serious.

And that hole in the ozone? Thats a fact. Its also a fact that the algae in the ocean, those things that produce around half the oxygen we breathe, cant tolerate much more UV radiation than what they are getting. When they start to die, we are in some serious shit, because they produce, as I said, a fucking lot of oxygen that we need. More than the entire Amazon.

Now if you tell me that humans havent caused that fucking hole in the ozone, I will tell you to jump off a bridge. If you tell me that global warming isnt at least being assisted by that shit we put into the air, same deal.

[squee]

I'm telling you that the shit they are trying to limit in order to reverse the ozone hole and all that stuff is NOT what is actually causing it. Ie, they (EPA, greenies, etc.) try to put controls on businesses--controls which are selectively enforced and have been for a long time--and they don't really give a shit about the environment, they care about money.

So if you are a corporation that dumps pure toxic slime into the ocean, you can get away with it if you donate money to a certain political candidate.

Dig?

Incidentally, if candidates were not allowed to accept any money from big businesses and whatnot, then this might not be such a problem.

Ding!

[TotalAnarchy]

Toxic waste in the oceans doesnt cause the world to stop breathing.

Greenhouse gases, such as CO2 and Carbon Monoxide, such as that released by cars, being big pollutants, as well as CFC's even though they have been cut down on alot, as well as a chemical cocktail of shit that goes in the air.

People produce these when they drive their 5lt 3tonne SUV's around the place. Or when they leave their lights on unneccesarily.

You know what would cause a massive drop in energy and therefore pollution consumption? If we payed a real price for energy. In other words, a world price for energy. Because the Western countries pay a very insignificant amount of what the true cost should be at.

[squee]

Ok, whatever, TA, you're not biting so I'm not fishing. I think you need to look at the motivations of these people a bit more. I think most of the anti-environmental rhetoric is bullshit but I think the environmentalists are full of shit too.

[Billyman]

*ahem* (http://www.thehypertribe.net/forum/showthread.php?s=&threadid=3355&highlight=Debunking)<-----------------click me!, click me!

[SimpleSimon]

Thanks Billy!

Now I don't need to repeat myself.

As for CFC's, perhaps they contribute to the ozone hole's increase in size, or perhaps they don't. What is certain is the FACT that Dow Chemicals patents on the most common refigerants had run out when this all became a "popular issue", and they were facing stiff competition in the world markets on a major product line of theirs. Lo and behold! the replacements, which are touted as "environmentally safer" are making them tons of money again.

Plot the growth in the size of the ozone hole against time, then plot the weakening of the earth's magnetic field (which is apparently dropping precipitously) over the same period. The curves are nearly identical. Then think about the effect a weakening of the magnetic field has on the incidence of ionizing radiation in the upper atmosphere.

Any questions?

[hardcoredana]

Nope, just a thank you for posting the article in the first place.

Thanks!

P.S. Ima hafta agree with MAC, Simon, and Squee on this one.

TA: why don't you stop swearing and start using some real debating skills?

[SimpleSimon]

Originally posted by TotalAnarchy
Toxic waste in the oceans doesnt cause the world to stop breathing.

Greenhouse gases, such as CO2 and Carbon Monoxide, such as that released by cars, being big pollutants, as well as CFC's even though they have been cut down on alot, as well as a chemical cocktail of shit that goes in the air.

People produce these when they drive their 5lt 3tonne SUV's around the place. Or when they leave their lights on unneccesarily.

You know what would cause a massive drop in energy and therefore pollution consumption? If we payed a real price for energy. In other words, a world price for energy. Because the Western countries pay a very insignificant amount of what the true cost should be at.

I added the color because I thought it appropriate to the political leanings made so obvious by the babbling going on in this post.

I seem to recall a certain young Aussie bragging on driving (daddies) Holden. Does that qualify as an economy car?

And there you go with should again. I asked before, and never got an answer: just what the hell does that statement mean? And who gets the privilege of deciding what energy "should" cost?

[philjit]

To sum up:

Global Warming/Greenhouse Effect: To terms often put together as meaning the same thing when they don't.

Fact: The planet is getting warmer.

Fact: Carbon Dioxide (CO2) output is higher than CO2 intake by forests and vegetation on a global scale.

Fact: CO2 cannot escape the atmosphere of the planet.

Fact: CO2 levels are increasing.

Fact: CO2 blocks UV and Infra red light, ergo heat, escaping from the atmosphere.

Dispute: How much of a part does this play in the warming of the planet when cyclic nature is taken into account?

CFC and Ozone Layer

Fact: CFC's deplete ozone.

Fact: The Larson B iceshelf is/was under the ozone hole.

Fact: The LArson B ice shelf has broken away.

Fact: Sea levels will nominally rise as a result of CFC usage.

Dispute: Its a conspiracy??

[SimpleSimon]

Originally posted by philjit
.....(snip)

CFC and Ozone Layer

Fact: CFC's deplete ozone.

Fact: The Larson B iceshelf is/was under the ozone hole.

Fact: The LArson B ice shelf has broken away.

Fact: Sea levels will nominally rise as a result of CFC usage.

Dispute: Its a conspiracy??

CFC's deplete ozone: Show me your proof.

Where is the causal relationship between posited fact one, and facts two and three. Also, demonstrate the causal relationship between facts two and three.

Posited fact four is not a fact at all, it is a conclusion, not supported by the first three.

[philjit]

Mate, CFCs have been shown to deplete ozone in laboratories. That is a fact.

As fopr the causal link. There is a hole in the ozone layer. That is a fact. That hole was, at certain times of the year over the Larson B Ice shelf, that is what caused it to melt and break away. We used to use CFCs massively, not just in fridges but as propellants for aersols. Now go an dpick up a copy of the Journal of Biochemistry, or the Journal of Chemisty, or the British juronal of Chemistry and you will find numerous articles on laboratory experiments that prove that CFCs deplete ozone.

Are you saying that the hole in the ozne is not there?

[philjit]

Originally posted by SimpleSimon
Posited fact four is not a fact at all, it is a conclusion, not supported by the first three.

rubbish. Are you saying that Larson B did not break away and is not floating into the Gulf Stream and will not melt causing a nominal rise in sea level. Note the word nominal. I didn't say there would be flooding or anything serious.

[Smug Git]

Originally posted by SimpleSimon

Plot the growth in the size of the ozone hole against time, then plot the weakening of the earth's magnetic field (which is apparently dropping precipitously) over the same period. The curves are nearly identical. Then think about the effect a weakening of the magnetic field has on the incidence of ionizing radiation in the upper atmosphere.

Any questions?

Yeah, I would like to see the graphs for a start, and also an explanation of why thry should match, then an explanation of why all the independent scientists (not funded by industry) have failed to see this apparently obvious connection. I have heard, from one source, a theory about a change in the magnetosphere changing the ionosphere and therefore screening less of the radiation from space, but that was in a work of fiction. I am not saying that it is not possible, just wondering why none of the experts appear to have spotted it, and also why a reduction in CFCs has accompanied, I believe, a reduction in the size of the whole in the ozone layer.

As for the rest of this, ask scientists in the field what is happening, and most will tell you that they think that the climate change is exacarbated by emissions from our industrial world. Medieval sea levels were not as high as predicted sea levels from this current cycle may rise, so I imagine that the scientists in your article are saying that the current cycle might be a short one that does not continue; if most of the scientific community are telling me that in their opinion this is not the case this time around, I am inclined to believe them rather than believe the minority and wait to see what happens. If the majority opinion changes, then I would have to follow that; they are not in the pocket of big business, as a rule, they are not going to make any significant money as a rule (although there are definitely some financial interests for some in this).

The only reason that I can see for believing that C02 emissions (for example) are not responsible for an increase in global warming, on majority scientific advice, is either that you are an expert in the field and have another model, or that you want to believe one explanation. I definitely want to believe that our actions have no effect on it all, but I don't see how I can.

Incidentally, there is no real connection, as far as I am aware, between global warming and the hole in the ozone layer (apart from that CFCs are implicated in the hole in the ozone layer and are also greenhouse gases).

[Koliedrus]

Originally posted by Smug Git


...
Incidentally, there is no real connection, as far as I am aware, between global warming and the hole in the ozone layer (apart from that CFCs are implicated in the hole in the ozone layer and are also greenhouse gases).

You just made one.

[Smug Git]

Originally posted by Koliedrus


You just made one.


Aha! But I said 'apart from'! I mount my logic steed and thunder into the joust, my semantic lance couched and my shield of science shining in the THT sunlight...

erm...

Too much fantasy literature for me, I think

[3MTA3]

CO2 is at almost .03% now...that is, it makes up that much of the earths atmosphere...it is rising because of us but I dont think its a serious problem, although we should limit emissions...to save trouble down the road...no problem in being proactive, eh?

Energy costs what it costs...although the majority of energy industries(as far as I know) in America are public, the private providers seem to compare comperable rates without taking subsidies...the market has already decided what it costs...as for a world price or whatever, Im not going to pay for some poor, ignorant fuck in Mongolia to have a night light...so screw that.

[Billyman]

Originally posted by philjit
Mate, CFCs have been shown to deplete ozone in laboratories. That is a fact.

As fopr the causal link. There is a hole in the ozone layer. That is a fact. That hole was, at certain times of the year over the Larson B Ice shelf, that is what caused it to melt and break away. We used to use CFCs massively, not just in fridges but as propellants for aersols. Now go an dpick up a copy of the Journal of Biochemistry, or the Journal of Chemisty, or the British juronal of Chemistry and you will find numerous articles on laboratory experiments that prove that CFCs deplete ozone.

Are you saying that the hole in the ozne is not there?

CFC's destroy the ozone, k, I'll accept that. But what isn't in that literature you've been reading is how the ozone has the capability to repair itself over and over. Only a portion of the "facts" are ever givin there. "They" only want you to know half the story period.

Yes, there is a hole in the ozone. How long has it been there? As far as scientist can tell, it's always been there. They have no proof, NO proof that "we" caused it. None, nada, zip. It's all speculation. "They" will print only part of the story as long as "they" see fit. And as long as you will read only that half.

Yes, the earth is warming up, soon (in a nother few centuries or so) it'll cool down again. Shit man, it's been happening since the begining of time as far as we can tell. That, they do have documented proof of. But you wont see that in every artical you read, oh no, the EPA wont allow it. Go get some facts, HARD COLD FACTS, and report back, until then, you're as gullible as most of the rest of the world. Wake up! Smell the coffee. Read all the articles, ALL of them.

FACTS, you need 'em. You obviosly don't have 'em all.

[SimpleSimon]

Originally posted by philjit
Mate, CFCs have been shown to deplete ozone in laboratories. That is a fact.

As fopr the causal link. There is a hole in the ozone layer. That is a fact. That hole was, at certain times of the year over the Larson B Ice shelf, that is what caused it to melt and break away. We used to use CFCs massively, not just in fridges but as propellants for aersols. Now go an dpick up a copy of the Journal of Biochemistry, or the Journal of Chemisty, or the British juronal of Chemistry and you will find numerous articles on laboratory experiments that prove that CFCs deplete ozone.

Are you saying that the hole in the ozne is not there?

Where are the links? Show me your proof. Laboratory tests showing ozone depletion in the upper atmosphere by CFC's are extremely problematic. It is viryually impossible to replicate those conditions (temperature, gas ratios, magnertic fields, insolation, etc.) on a large enough scale in controlled conditions to state conclusively what mechanisms cause what results.

The fact that the "hole" in the ozone layer (actually a localized thinning) was over the Larson B ice shelf has not, in any peer-reviewed publication of which I am aware, been shown in any way to have a causal link to the breakup of the ice shelf.

Originally posted by Philjit

Originally posted by SimpleSimon
Posited fact four is not a fact at all, it is a conclusion, not supported by the first three.



rubbish. Are you saying that Larson B did not break away and is not floating into the Gulf Stream and will not melt causing a nominal rise in sea level. Note the word nominal. I didn't say there would be flooding or anything serious.

Please note, the Gulf Stream is a major circulatory mechanism of the North Atlantic, not the South Pacific. Thus, Larson B is not floating into it.

Originally posted by Smug Git


Yeah, I would like to see the graphs for a start, and also an explanation of why thry should match, then an explanation of why all the independent scientists (not funded by industry) have failed to see this apparently obvious connection. I have heard, from one source, a theory about a change in the magnetosphere changing the ionosphere and therefore screening less of the radiation from space, but that was in a work of fiction. I am not saying that it is not possible, just wondering why none of the experts appear to have spotted it, and also why a reduction in CFCs has accompanied, I believe, a reduction in the size of the whole in the ozone layer.

Fair enough. I will post the link once I have sufficient time to locate it again. By the way, reduction in CFC emissions has not significantly reduced the size of the "hole" in the ozone layer.

As for the rest of this, ask scientists in the field what is happening, and most will tell you that they think that the climate change is exacarbated by emissions from our industrial world. Medieval sea levels were not as high as predicted sea levels from this current cycle may rise, so I imagine that the scientists in your article are saying that the current cycle might be a short one that does not continue; if most of the scientific community are telling me that in their opinion this is not the case this time around, I am inclined to believe them rather than believe the minority and wait to see what happens. If the majority opinion changes, then I would have to follow that; they are not in the pocket of big business, as a rule, they are not going to make any significant money as a rule (although there are definitely some financial interests for some in this).

Financial interests have many determinants. Virtually every "climatologist" receives support from a primary source directly traceable to government. The EPA, the various other alphabet soup agencies, and the major industrial players all have similar agendas with regard to the power (and wealth) to be derived from controlling public fears.

The only reason that I can see for believing that C02 emissions (for example) are not responsible for an increase in global warming, on majority scientific advice, is either that you are an expert in the field and have another model, or that you want to believe one explanation. I definitely want to believe that our actions have no effect on it all, but I don't see how I can.

I have neither said nor implied that increasing CO2 levels are not a factor in global warming. What I have said is that the major factors in the increase are not necessarily industrial activity. Take a look at the estimates for total CO2 and methane emissions by grazing animals worldwide. Both are 'greenhouse" gases.

Incidentally, there is no real connection, as far as I am aware, between global warming and the hole in the ozone layer (apart from that CFCs are implicated in the hole in the ozone layer and are also greenhouse gases).

[SimpleSimon]

http://nsidc.org/iceshelves/larsenb2002/index.html

Antarctic Ice Shelf Collapses

Posted: 18 March 2002
Updated: 21 March 2002 14:40 MST

Recent Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery analyzed at the University of Colorado's National Snow and Ice Data Center revealed that the northern section of the Larsen B ice shelf, a large floating ice mass on the eastern side of the Antarctic Peninsula, has shattered and separated from the continent. The shattered ice formed a plume of thousands of icebergs adrift in the Weddell Sea. A total of about 3,250 km2 of shelf area disintegrated in a 35-day period beginning on 31 January 2002. Over the last five years, the shelf has lost a total of 5,700 km2, and is now about 40 percent the size of its previous minimum stable extent.

Ice shelves are thick plates of ice, fed by glaciers, that float on the ocean around much of Antarctica. The Larsen B shelf was about 220 m thick. Based on studies of ice flow and sediment thickness beneath the ice shelf, scientists believe that it existed for at least 400 years prior to this event, and likely existed since the end of the last major glaciation 12,000 years ago (see more about Dr. Eugene Domack's research).

For reference, the area lost in this most recent event dwarfs Rhode Island (2717 km2) in size. In terms of volume, the amount of ice released in this short time is 720 billion tons, enough ice for about 12 trillion 10 kg bags.

This is the largest single event in a series of retreats by ice shelves in the Peninsula over the last 30 years. The retreats are attributed to a strong climate warming in the region. The rate of warming is approximately 0.5 degrees Celsius per decade, and the trend has been present since at least the late 1940s. Overall in the Peninsula, extent of seven ice shelves has declined by a total of about 13,500 km2 since 1974. This value excludes areas that would be expected to calve under stable conditions.
Ted Scambos, a researcher with the National Snow and Ice Data Center (NSIDC) at University of Colorado, and a team of collaborating investigators, developed a theory of how the ice disintegrates. The theory is based on the presence of ponded melt water on the surface in late summer as the climate has warmed in the area. Meltwater acts to enhance fracturing of the shelf by filling smaller cracks and forcing them through the thickness of the ice due to the weight of the water. The idea was suggested in model form by other researchers in the past (Weertman, 1973; Hughes, 1983); satellite images have provided substantial observational proof that it is in fact the main process responsible for the Peninsula shelf disintegrations. Christina Hulbe of Portland State University and Mark Fahnestock of University of Maryland collaborated with Scambos on the research.

A number of international scientists have also cooperated in the general study of the demise of the shelves and the climatic trend in the Antarctic Peninsula. As early as November of last year, Pedro Skvarca, Head of the Glaciological Division of the Instituto Antártico Argentino, warned of a possible impending breakup, due to very warm spring temperatures and a dramatic 20 percent increase in the rate of flow of the ice shelf. He and his team were the last people to set foot on the northern portion of the shelf. Later in the summer, the Argentine group returned to their base at Marambio, near the shelf, to await what they anticipated would be the final disintegration event. They flew over the shelf repeatedly, measuring its extent with GPS during the course of the breakup event. (See Dr. Skvarca's photos of the ice front line towards Cape Foyn and the broken ice shelf south of the Seal Nunataks.)

A British research vessel, the RRS James Clark Ross, was in the area just as the event was occurring and provided images from the ocean surface in the region of the event. Keith Nicholls of British Antarctic Survey (BAS) provided the images.

In prior studies, Dr. David Vaughan and Chris Doake of BAS have reported extensively on the climate warming in the area, and have modelled shelf stresses and possible causes of breakup. They collaborated with Skvarca and with Austrian and German scientists, Dr. Helmut Rott and Dr. Wolfgang Rack, who conducted detailed satellite radar image studies and field studies in the area. The radar study also showed ice flow increase in the years leading to breakup and an increased velocity of the glaciers as the shelves disappeared. Radar images have provided very detalied views of the events of past ice shelf collapses. Dr. Rott is a professor at the Department of Meteorology and Geophysics at Innsbruck University; Dr. Rack is now at Alfred Wegener Institute in Bremerhaven, Germany.

The melt water fracturing theory fared well in this last event (See Christina Hulbe's Larsen Ice Shelf site). Sequential images from the MODIS sensor, a new satellite imager flying on NASA's Terra platform, showed extensive melt ponding over the Larsen B in late January, consistent with an unusually warm summer and extended melt season. In a series of images taken in February, several of the melt ponds disappeared, presumably as they drained through opening fractures in the ice. By 23 February, 790 km2 had shattered from the front. The next image from 5 March showed another 1960 km2 of ice gone. The event continued to 7 March with an additional loss of 525 km2. The area lost by the shelf was was almost solely the region covered by melt ponds in late January. The timing of the event, at the end of a particularly warm summer, is consistent with the theory.

Other scientists, and Scambos, continue to look for additional mechanisms that may contribute to the breakups. One idea is that meltwater seeping between ice crystals and warming of the shelf as a whole, reduces the fracture toughness of the ice so that the shelf shatters under the same stresses imposed by local geography and the flow it used to tolerate. Another idea is that meltwater seeps into shallow cracks and expands the cracks as it refreezes during the winter. Ocean warming and sub-ice currents dragging on the underside of the ice have also been cited as possible contributors.

While the breakup of the ice shelves in the Peninsula has little consequence for sea level rise, the breakup of other shelves in the Antarctic could have a major effect on the rate of ice flow off the continent. Ice shelves act as a buttress, or braking system, for glaciers. Further, the shelves keep warmer marine air at a distance from the glaciers; therefore, they moderate the amount of melting that occurs on the glaciers' surfaces. Once their ice shelves are removed, the glaciers increase in speed due to meltwater percolation and/or a reduction of braking forces, and they may begin to dump more ice into the ocean than they gather as snow in their catchments. Glacier ice speed increases are already observed in Peninsula areas where ice shelves disintegrated in prior years.

With the Peninsula shelf breakups as a guide, we can now reassess the stability of ice shelves around the rest of the Antarctic continent. Past assessments of stability were based primarily on mean annual temperature; with this guideline, most shelves outside the Peninsula were considered well within their climate limit. Given the success of the melt pond theory, we use the climate conditions and physical parameters of ice shelves at the point of ponding as a guide in this assessment. In particular, the next shelf to the south, the Larsen C, is very near the stability limit, and may start to recede in the coming decade if the warming trend continues. Melt ponds are occasionally observed in limited regions of the Larsen C shelf. More importantly, the warmest part of the giant Ross Ice Shelf is in fact only a few degrees too cool in summer presently to undergo the same kind of retreat process. The Ross Ice Shelf is the main outlet for several major glaciers draining the West Antarctic Ice Sheet, which contains the equivalent of 5 m of sea level rise in its above-sea-level ice.

Although several recent large iceberg calving events have been observed on the Ross and elsewhere in Antarctica, none of these are thought to be related to ice shelf instability.

Please note, the warming trend in the Antartic has been ongoing for at least 60 years. It began well before the use of CFC's was at all common, globally.

[Pianomahnn]

I came across this comic while reading the paper this morning. I found it very fitting. :)

[Smug Git]

Originally posted by SimpleSimon

Take a look at the estimates for total CO2 and methane emissions by grazing animals worldwide. Both are 'greenhouse" gases.



Emissions from farming practices are just recycling of atmospheric CO2; plants take it in during photosynthesis and some of it is used to create their structure and then when they rot or are eaten, they return that CO2 to the atmosphere (the CO2 that is released from ploughing is also simply a return to the atmosphere of CO2 that was recently part of the atmosphere). This is why the CO2 released from burning wood is not a problem. Fossil fuel burning, however, will increase Carbon levels to a level that they were at the sort of time that the fuels were laid down; problematically, we have spread, since then over a large part of the surface area of the globe.

I am doing a PhD in physics (used to be a physics teacher), although not in this field; I work on the same floor as the atmospheric physicists and I do know one of them well enough, as she is a friend of one of my friends. She is not a wild-eyed pinko environmentalist and yet she says that on balance of probabilities that human activity is exacarbating global warming. I repspect her expertise, neutrality and intelligence, and also that of the scientific community as a whole (the government funded research in physics at universities in this country (and I suspect elsewhere) is really most definitely not leaned on by government). The simplest explanation is that it is really happening, to a degree that may never be known.

Also someone mentioned that the level of CO2 in the atmosphere is only 0.03%; this is absolutely true, and is in fact part of the problem because it is therefore easier to achieve a larger fractional change in that percentage (ie, a smaller absolute quantity of 'fossil' CO2 is required to achieve that).

[Billyman]

Originally posted by Smug Git

The simplest explanation is that it is really happening, to a degree that may never be known.


This is why I stand firm on saying there is NO facts and NO proof. I stand firm in my beliefs that we didn't start this problem nor do we contribute to it as everyone thinks. We don't help the prob. i'm sure but we can't take all the blame.

I'm merely asking a question, it's seems I read something somewhere that volcanoes emit ozone damaging gases as well. Is this correct?

[Pianomahnn]

Volcanos kick out some rank shit. More shit than us humans do, I'm sure.

One can't see the emissions from a factory across the planet...but when one of those big fuckers lets loose, it can, and will be seen across the planet.

One reason why the very early earth was so nasty; volcanos and other funktified shit coming up from below. It's just a lot less frequent/intense now.

[Smug Git]

Originally posted by Billyman


This is why I stand firm on saying there is NO facts and NO proof. I stand firm in my beliefs that we didn't start this problem nor do we contribute to it as everyone thinks. We don't help the prob. i'm sure but we can't take all the blame.

I'm merely asking a question, it's seems I read something somewhere that volcanoes emit ozone damaging gases as well. Is this correct?


I don't have anything as firm and rigid as a belief, I just trust the majority of scientists and if their opinion does change, then I will change with them; their arguments are all scientifically plausible, there are no aburdities in there so I wouldn't laugh at them by any means.

I wouldn't be surprised if ozone damaging gases are emitted from volcanoes but that wouldn't mitigate the human effect, obviously. Bondo, at the asylum (although infrequently) would know more, and also whether they are simply recycing said gases or whether they are, over time, increasing the proportion of said gases in the atmosphere and also how that would compare with the rate of human production of ozone-depleting gases.

As far as the debate about whether CFC's harm ozone, the chemical reaction is known and the energetic favourability and also the activation energy would also be known (an energetically favourable reaction will take place, but the activiation energy will affect the rate); given this, I imagine that the only question was 'are there CFCs up there, and how many' and wasn't that tested with high-altitude balloons?

I will say, though, that my main interest is in global warming and not in the hole in the ozone layer (until I read this thread, I didn't even know that there was any real debate left on this; I have even taught it on the National Curriculum at high school level I think).

[mute]

Iheard global warming leads to an ice age? That's probably wrong but I remember hearing it a long time ago...

About that ice berg, I was listening to the radio and this scientist talk about the glaciers and how there's a huge piece of glacier that will break(at most in 30 years) that will create a huge tidal wave and destroy most coastal areas and raise the sea level 100 feet(i think that's what he said).

I think I hear the wrong things. Good thing I don't believe em to be all that true...

[SimpleSimon]

For you eco-freak types who are so concerned about global warming and the breakup of the Antarctic ice-cap, I thought you might like to see this.

There truly is no cause for alarm.

http://www.natice.noaa.gov


Antarctic Icebergs Seen As Normal

By RANDOLPH E. SCHMID Associated Press Writer
published 02:33 PM - MAY 23, 2002 Eastern Time

WASHINGTON (AP) _ The icebergs breaking away from Antarctica in recent months _ some as big as small states _ are part of a process scientists say marks a return to ice conditions of years past.

Several ice shelves around the continent have been growing in recent years, a process that has puzzled researchers concerned about possible global warming.

In the last three months _ autumn there _ several icebergs, one the size of Delaware and another nearly as big as Chesapeake Bay, have broken free.

"The icebergs that have calved in last couple of months probably don't have much to do with global warming. It is part of a pattern of growth and retreat that is more or less normal," explained Ted Scambos of the National Snow and Ice Data Center at the University of Colorado.

University of Chicago researcher Douglas MacAyeal, who placed automated weather stations and tracking devices on one of the new icebergs, said the satellite and other technologies are allowing science for the first time to observe the birth of such large bergs.

The process, he said, is part of a natural cycle in which ice shelves grow and then calve icebergs over geological time scales.
A couple of the ice shelves along the coasts of the continent, particularly the Ross and Ronne shelves, have become more extended than they were in the past and are now returning to the limits that were normal from about the 1950s to the 1970s, Scambos said.

Scientists are also much better able to track these icebergs using satellites, Scambos noted. "Anytime an event occurs we're on it in a day or two."

"It's a grand event, it's astounding event," when these bergs break loose, he said. "But it probably should not cause alarm ... the shelves that are calving don't seem to be retreating past their minimum historical extent."

He added, however, that scientists don't have good long term records of Antarctic sea ice limits.

H. Jay Zwally of the NASA Goddard Space Flight Center in Greenbelt, Md., reports in the June issue of the Journal of Geophysical Research-Oceans that the amount of floating sea ice surrounding Antarctica has increased about 1 percent per year over the last 20 years.

The increasing amount of floating ice results from a combination of processes including changes in salinity and the amount of overturning of the water. Water with less salt freezes more easily and reducing the rising and falling ocean water means less heat comes up from below.

This is occurring "possibly despite global warming and possibly as a result of global warming," he said.

At the same time, at the other end of the planet, Arctic ice has been decreasing.

And there is also melting on the Larsen Ice Shelf at the Antarctic peninsula that extends toward the tip of South America.
The collapse of that shelf, much farther north than the Ross and Ronne shelves, is thought to be related to temperature increases in that region.

Larsen and the Antarctic peninsula "have experienced an unusual and profound warming trend," Scambos said. "Ice shelves that had existed several thousand years are retreating. The surprise is how fast the turnaround occurred."

Satellite images show that the piece of the Larsen Ice Shelf collapsed durin g a five-week period that ended March 7. It splintered into a plume of drifting icebergs. The Larsen Ice Shelf has been under careful observation since 1995, when its northernmost sector collapsed in a similarly dramatic event. The shelf now is about 40 percent of its original size.

But glaciers elsewhere on the continent are both thickening and thinning as temperatures show conflicting climate trends.

[Smug Git]

This goes back to my thing about there being many different opinions. The vast moajority, I believe, say that global warming is happening and that it will cause a significant rise in sea levels. The debate is whether it is 'natural'; there is a clear mechanism which could link humans to the warming which has not been refuted, but there have also been significant 'natural' changes in temperature on the earth in the past too.

Talk of amounts of ice is misleading the debate, which should be about average temperatures; arctic ice is completely irrelevant to rising sea levels (only peripherally mentioned in the article there, but you do hear other people talking about it) because that ice is already floating. Even without melting ice, there will be a rise in sea levels due to warming and expansion of the top layer of water; in any case, the melting of ice is probably going to lag behind global warming due to water's very high specific latent heat of fusion. The ice looks good on TV, and may well be linked to global warming (this article is no more definite than the ones that say that it is due to global warming)(it is also worth noting that Scambos is the only one in this making a definite statement about it not being a cause for alarm) but the fact that any global warming effects have to be distinguished from natural fluctuations in the ice will always allow vested interests to muddy the scientific debate (as well as scientists simply seeking personal 'fame' or notoriety).

I think Mute needn't worry that one berg is going to cause a rise in sea level of 100 feet, though. Also, I will repeat that floating ice won't cause a rise in sea levels when it melts, it is ice that is on land that causes problems when it's water flows down to the sea, and also expansion of water already in the sea due to rises in global temperature; these are the two factors that will cause a rise in sea levels.