Debates
16 Nov 07
22 Nov 07
Originally posted by kmax87Sure, but did those EuroScientists bother to figure out why the ice is melting or did they just make the assumption that it was global warming?
On the other hand heres an article from wiki news about polar ice cap melting that I had not thought had gotten this serious.........
http://en.wikinews.org/wiki/Arctic_ice_levels_at_record_low_opening_Northwest_Passage
A small excerpt:-
16/11/07
"According to the European Space Agency (ESA), 200 satellite images from the Danish National Space Center ...[text shortened]... 0, all of the summer ice could be gone with the region being completely ice free by 2070. ."
http://www.jpl.nasa.gov/news/news.cfm?release=2007-131
22 Nov 07
Originally posted by MerkDid you bother to read the wiki? All it says is that the ice has withdrawn further than at any point in recorded history. Go read the wiki, there is no mention of potential causes. So no assumptions were made by those EuroScientists as you call them. The space agency took and posted data, and is leaving the interpretation to experts. If only some of your more politically leaning posts could do the same.
Sure, but did those EuroScientists bother to figure out why the ice is melting or did they just make the assumption that it was global warming?
http://www.jpl.nasa.gov/news/news.cfm?release=2007-131
As for the link you put in this post, here's my favourite line...
Morison cautioned that while the recent decadal-scale changes in the circulation of the Arctic Ocean may not appear to be directly tied to global warming, most climate models predict the Arctic Oscillation will become even more strongly counterclockwise in the future.
and...
"While some 1990s climate trends, such as declines in Arctic sea ice extent, have continued, these results suggest at least for the 'wet' part of the Arctic -- the Arctic Ocean -- circulation reverted to conditions like those prevalent before the 1990s," he added.
That's the bit where he says his research, dealing with flow, is not relevant to the ice cover, the article you posted is about sea currents, not ice cover, and the author of the paper itself says so. I don't see how you think this counters global warming.
23 Nov 07
Originally posted by agrysonHold on a minute here. Are you saying that ice cover and current aren't related? If so, we gotta talk about that deal were Britain is supposedly going to freeze when the warm currents stop coming up from the Gulf of Mexico (or wherever the hell they come from_ when the ice cap melts.
Did you bother to read the wiki? All it says is that the ice has withdrawn further than at any point in recorded history. Go read the wiki, there is no mention of potential causes. So no assumptions were made by those EuroScientists as you call them. The space agency took and posted data, and is leaving the interpretation to experts. If only some of your mor ...[text shortened]... thor of the paper itself says so. I don't see how you think this counters global warming.
More to your question though, it's this part in the first paragraph.
" The results suggest not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming."
23 Nov 07
Originally posted by MerkI didn't say they had nothing to do with them, I simply quoted, from your own link, where the expert ont he subject, the expert you chose, warned reader that they were two different things and that his research should only be referred to in reference to the "wet" arctic ocean. I quoted your own scientist where he said that the two were not to be considered analogous. That is not the same as saying they have nothing to do with eachother, but that they are not the same thing.
Hold on a minute here. Are you saying that ice cover and current aren't related? If so, we gotta talk about that deal were Britain is supposedly going to freeze when the warm currents stop coming up from the Gulf of Mexico (or wherever the hell they come from_ when the ice cap melts.
More to your question though, it's this part in the first paragraph.
" T ...[text shortened]... ic climate in recent years are a result of long-term trends associated with global warming."
As for that bit in the first paragraph... "suggest not all". Read the article, because it seems it was only the first paragraph you read when you first decided to post it. The article simply says that there is a pattern to the arctic currents, and then goes on to say that this pattern is likely to become more erratic as a result of global warming, you should really read the links you post...
23 Nov 07
Originally posted by MerkThermohaline circulation otherwise known as The Atlantic Conveyor uses the Gulf Stream to keep Britain and Northern Europe warmer than their latitude would indicate.
Hold on a minute here. Are you saying that ice cover and current aren't related? If so, we gotta talk about that deal were Britain is supposedly going to freeze when the warm currents stop coming up from the Gulf of Mexico (or wherever the hell they come from_ when the ice cap melts.
More to your question though, it's this part in the first paragraph.
" T ...[text shortened]... ic climate in recent years are a result of long-term trends associated with global warming."
Warmer = less density Fresh Water = less density
Colder Water = more density Saltier Water = more density
At present the Atlantic Conveyor is keeping the Gulf Stream current on top of the (colder/denser) salt water in the Northern Atlantic enabling the transfer of the gulf warmth to the countries in the North Atlantic region.
However, as more and more ice pack melts more Fresh Water (less dense) enters into the mix and will float over the Salty (more dense) Gulf Stream and force it into abyssal plain of the Atlantic, effectively shutting down the Atlantic Conveyor.
This will cause meaningful temperature change…ice-skating on Thames anyone?
The upside is, this colder temperature will cause more fresh water to form into artic ice thus turning the Atlantic Conveyor on again. No more skating on Thames...aack its warming!
The downside is the re-start of Atlantic Conveyor will cause temps to once again rise and shut the Atlantic Conveyor off again. Skating on Thames once more…aack its cooling!
Get the picture? Although a complete cycle takes a very long time to complete, this has been going on forever and will continue.
23 Nov 07
Originally posted by MacSwainWhat is known is that the NAD has remained relatively stable for 40 years and has thus not been the cause of the most recent dramatic melting of arctic ice, so your rather simplistic theory of swings and roundabouts isn't really taking into account all that it should.
...this has been going on forever and will continue.
23 Nov 07
Originally posted by agryson"so your rather simplistic theory"
What is known is that the NAD has remained relatively stable for 40 years and has thus not been the cause of the most recent dramatic melting of arctic ice, of swings and roundabouts isn't really taking into account all that it should.
Not a theory it exists...certainly NOT my creation.
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1) Are you desputing the existance of the Atlantic conveyor?
2) Are you desputing the cycles of the Atlantic Conveyor?
Simple yes/no answer to those two questions would be nice.
23 Nov 07
Originally posted by MacSwainNo and yes (kind of), what I'm disputing is your link between it and arctic ice cover. If as your theory suggests (I only assume it's yours because there's no link to supporting material or even a reference to whose it is) arctic ice cover and NAD are linked in that way, it fails to take into account the fact that the NAD has been stable for 40 years and counting (that's just since satellites, Benjamin Franklin was still seeing it back in his time), while arctic ice cover has most definitely not.
"so your rather simplistic theory"
Not a theory it exists...certainly NOT [b]my creation.
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1) Are you desputing the existance of the Atlantic conveyor?
2) Are you desputing the cycles of the Atlantic Conveyor?
Simple yes/no answer to those two questions would be nice.[/b]
Why would arctic ice cover be changing so dramatically if the NAD has not unless your theory is missing something... like the human element perhaps?
23 Nov 07
Originally posted by agrysonCome on now...get off it. 🙂 You are disputing "yes (kind of)" the cycles of the Atlantic Conveyor. Why the qualified (kind of)? You can't force yourself into denying what you know to be true. LOL
No and yes (kind of), what I'm disputing is your link between it and arctic ice cover. If as your theory suggests (I only assume it's yours because there's no link to supporting material or even a reference to whose it is) arctic ice cover and NAD are linked in that way, it fails to take into account the fact that the NAD has been stable for 40 years and ...[text shortened]... ly if the NAD has not unless your theory is missing something... like the human element perhaps?
A supremely over-educated individual such as yourself knows chapter and verse of this most basic natural activity. Quit playing dumb just to make a point.
And asking for "link to supporting material"..Ha!..any school boy knows all pertinent facts regarding this cyclical activity. You are playing to an audience my friend - leaving me under impressed. 🙂
23 Nov 07
Originally posted by MacSwainIndulge me with a link then, or at the very least (as I also asked, though you did not include it in your quote a name) I know the NAD goes through cycles, but that those cycles are linked to arctic ice cover reducing to the levels we see today is something I have never heard of... in fact it's something no human in recorded history has ever heard of. So excuse my ignorance, feigned or not.
Come on now...get off it. 🙂 You are disputing [b]"yes (kind of)" the cycles of the Atlantic Conveyor. Why the qualified (kind of)? You can't force yourself into denying what you know to be true. LOL
A supremely over-educated individual such as yourself knows chapter and verse of this most basic natural activity. Quit playing dumb just to make a poi ...[text shortened]... clical activity. You are playing to an audience my friend - leaving me under impressed. 🙂[/b]
24 Nov 07
Originally posted by agrysonWait a second, so all the people on this site crying about the ice cap melting and changing the conveyor (I guess it's called) pulled it out of thin air?
Indulge me with a link then, or at the very least (as I also asked, though you did not include it in your quote a name) I know the NAD goes through cycles, but that those cycles are linked to arctic ice cover reducing to the levels we see today is something I have never heard of... in fact it's something no human in recorded history has ever heard of. So excuse my ignorance, feigned or not.
24 Nov 07
Originally posted by MerkNo, read the post, I accept there is a link, of course there is, the NAD depends on water density, the density depends on ice cover which in turn effects reflection of sunlight. What I'm saying, and read this bit carefully...
Wait a second, so all the people on this site crying about the ice cap melting and changing the conveyor (I guess it's called) pulled it out of thin air?
"arctic ice cover reducing to the levels we see today is something I have never heard of"
I added emphasis this time. Of course natural cycles exist, that has never been disputed, that what we see today can be put down to natural cycles exclusively is ridiculous.
This ice cover change we see most recently is obviously not part of the cycle we've seen in the past because there has been no change in the NAD that would instigate the greatest melting of ice ever recorded in human history. Given that changes in the NAD cannot be responsible for this recent melting, the natural cycle quoted by MacSwain cannot be responsible.
24 Nov 07
Originally posted by agrysonHello again. First of all - My last post, when I read it just now..seems caustic in tone, I did not intend that tone and apologize if you found offense for that reason. 🙁
No, read the post, I accept there is a link, of course there is, the NAD depends on water density, the density depends on ice cover which in turn effects reflection of sunlight. What I'm saying, and read this bit carefully...
"arctic ice cover reducing to the levels we see today is something I have never heard of"
I added emphasis this time. Of co ...[text shortened]... onsible for this recent melting, the natural cycle quoted by MacSwain cannot be responsible.
1) For a link - put "Atlantic Conveyor" into your search engine and you will find loads of links.
2) You're incorrect in this post re: water density depending on ice cover and reflection of sunlight having something to do with the conveyor.
2a) Water density depends on saline content and temperature.
3) There are other factors that you have failed to take into account in your theory. These taken into combination plus the Atlantic Conveyor cannot be ignored. I will post the Milankovitch Theory for your information.
24 Nov 07
1 edit
In addition to the Atlantic Conveyor, this supplies an additional 3 items left out of your theory.
The Milankovitch Theory.
The earth’s axis it tilted some 23 ½ degrees. Changes in the "tilt" of the earth can change the severity of the seasons - more "tilt" means more severe seasons - warmer summers and colder winters; less "tilt" means less severe seasons - cooler summers and milder winters.
The earth wobbles in space so that its tilt changes between 22 and 25 degrees on about a 41,000 year cycle. It’s warm summers that allow snow and ice to melt more quickly than accumulation in high altitudes, eventually resulting in less massive ice sheets. There are positive feedbacks in the climate system as well, because an earth covered with less snow reflects less of the sun's energy into space, causing additional warming. In addition, the amount of Carbon Dioxide in the atmosphere increases as ice sheets melt, also adding to the warming of the climate. The converse is true when the opposite extreme of the tilt is reached. It’s cool summers that decrease snow and ice melt and causes Carbon Dioxide to decrease as the ice sheets build.
Additionally, the earth's orbit around the sun is not circular, which means the earth is slightly closer to the sun at some times of the year than others. The closest approach of the earth to the sun is perihelion, and it now occurs in January, making northern hemisphere winters milder. This change in timing of perihelion is known as the precession of the equinoxes, and occurs on a period of 22,000 years. 11,000 years ago, perihelion occurred in July, making the seasons more severe than today.
The "roundness", or eccentricity, of the earth's orbit varies on cycles of 100,000 and 400,000 years, and this affects how important the timing of perihelion is to the strength of the seasons.
The combination of the 41,000 year tilt cycle and the 22,000 year precession cycles, plus the smaller eccentricity signal, affect the relative severity of summer and winter, and control the growth and retreat of ice sheets. Warmer summers shrink ice sheets by melting more ice than the amount accumulating during the winter.
24 Nov 07
Also to add information for we laymen. Air temperature relates to the amount of corbon dioxide it can contain.
We all are aware that warm air can contain more humidity than cold air. (This creates rain when the two fronts come together)
In the same way, the warmer the air - the more carbon dioxide it will contain. Please add this into consideration when thinking of the Milankovitch Theory and the ramifications of this fact on what we are experiencing today.