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Failing Ocean Current Raises Fears of Mini Ice Age
Designadrug writes "This article from Newscientist paints a picture of a major climate control mechanism teetering on the brink:
"The ocean current that gives western Europe its relatively balmy climate is stuttering, raising fears that it might fail entirely and plunge the continent into a mini ice age. The dramatic finding comes from a study of ocean circulation in the North Atlantic, which found a 30% reduction in the warm currents that carry water north from the Gulf Stream.""
Depending on whom you ask, this could be a global warming issue. This is something I researched back in high school and got weird looks, but the logic goes like this:
1. Temperature warms up. Surface ice in the northern/southern reaches melt. This is something we've been seeing with the shrinking glaciers/nothern ice cap/Antartic icebergs melting.
2. Ocean rises, which causes a lowering of the ocean temperature from the influx of cold water.
3. With ocean levels higher, the ocean is able to absorb more energy, which shuts down the warm ocean currents.
4. Without the warm ocean currents, weather patterns are altered. Cold air that would have been warmed by the ocean currents remain cold. In time, the water that melted is converted into ice.
5. With the altered weather patterns and no warm air, the ice age comes into being. The more ice that forms, that more sunlight redirected back into space.
6. This continues until enough build up of ocean warmth.
Or - something like that. It's been a decade or two since I studied it, and I'm sure a meteorologist would do a better job. But what I do recall is that a good chunk of research shows this process can take place in as little as three years - which means it might be a good time to start buying some land down in Mexico....
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The temperature differential that drives that current has shrunk slightly and therefore as lost some momentum. Then Europe gets cold for a while, things even out, and everyone is happy.
Not really. Europe, and North America get colder yes (and to be honest I'm not all that happy about that, living in Canada at the moment), but the rest of the trapped heat from global warming doesn't magically vanish, it simply gets pushed elsewhere - so think more more heat (and droughts) for Africa, more energy in the Carribean to help power hurricanes etc.
This is why the term "global climate change" is preferred these days. While there is "global warming" in that there is more energy trapped and retained in the system, that doesn't mean it's going to be evenly distributed as warming, it just means more energy in the system which can result in more dramatic swings and changes in climate.
Jedidiah.
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original article in Nature
news article in Nature
Actually the movie was based on info and theories from the Woods Hole Oceanographic Institution. They just added a bunch of bad science for plot devices. Take a look at these two links: Little Ice Age and Abrupt Climate Change
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The article only mentions 5 data points over ~50 years, 1957, 1981, 1992, 1998 and now 2005.. which is not a lot to go on, likewise it mentions that the last time the current stopped was 12,000 years ago, at the end of the last Ice Age, and that it may have slowed down between 1300-1850 which was a "mini" ice-age.
I assume that the last 2 things were speculation, since the only way I could think of these things being measured is if it's somehow preserved in glacial layers etc.. could anyone who knows more explain what types of evidence back up these long term speculations? And if not, why we should draw any major conclusions from 5 data points over 50 years, when we don't know the variance of the system over hundreds or thousands of years, which 'seems' to be a 'normal' timescale for change?
I'm not saying this isn't a big deal, but the information in the article is woefully incomplete.
Global warming is a bit of a misleading name. Yes, the average temperature of the planet will go up, but that does not mean all places on the planet will increase in temperature. Before this, many scientists speculated that global warming would result in far colder, harsher winters for the United Kingdom.
The one thing about global warming that people must understand is that it will throw all the climate regions into chaos, and change them, which will change the local fauna and flora.
// file: mice.h
#include "frickin_lasers.h"
http://www.wunderground.com/education/abruptclimat e.asp
Here is the part I wanted to reference: "Since the Great Ocean Conveyor belt is driven in part by differences in ocean water density, if one can pump enough fresh water into the ocean in the key areas on either side of Greenland where the Gulf Stream waters cool and sink, this will lower the ocean's salinity (and therefore its density) enough so that the waters there no longer sink. The Atlantic conveyor belt and Gulf Stream current will then shut down in just a few years, dramatically altering the climate. "
Also here is a write up specifically dealing with the "science" of "The Day After Tomorrow."
http://www.wunderground.com/education/thedayafter. asp
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If the current is pulling all that energy from the warm waters up north and dissipating it in the process, what will happen to all the excess warmth if the current stops? Will it find another way to go? Maybe create a new current or even restart the same current again? That heat has to go somewhere, it is water after all.
Well the current that pushes northward occurs due to the conveyor effect that occurs when the water reaches up north, cools, sinks, and flows back as cold water much deeper. In general the current just circles around the equatorial Atlantic, and only a portion branches north due to said conveyor. If the conveyor effect stalls the most likely outcome is simply more and warmer water circulating in the equatorial Atlantic. That, of course, is going to have significant impacts on climate in Africa and central and South America. Potentially a lot of the energy may end up providing more power for hurricanes out in the Atlantic. What exactly will happen is unclear, but I think its safe to say that assuming everything will magically right itself is betting on the long shot - there's really no evidence for such a thing. The most likely outcome is simply a lot warmer and more energetic weather for Africa and South and Central America.
Jedidiah.
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Not that Kyoto would do jack anyway.U p.htm
http://www.junkscience.com/MSU_Temps/Kyoto_Count_
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True, ocean currents will still move. They're definitely chaotic system and often behave "counterintuitively".
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But all that warm water goes so far north largely because of (cold) water with high salinity. This water is dense and sinks. This is called North Atlantic Deep Water formation, and possibly drives deep ocean currents around the world.
This salinity gradient is the key energy source that "pulls" warm water so far north, more than the thermal or momentum gradients.
This gradient broke down during "the Younger Dryas cold episode, which chilled the North Atlantic region from 11,000 to 10,000 yr BP." "[This] is postulated to be a turnoff [...] of the North Atlantic's conveyor-belt circulation system which currently supplies an enormous amount of heat to the atmosphere over the North Atlantic region. This turnoff is attributed to a reduction in surface-water salinity, and hence also in density, of the waters in the region where North Atlantic Deep Water (NADW) now forms." Paleoclimate claims are supported by oxygen and carbon isotope studies on plankton.
see http://www.nature.com/nature/journal/v341/n6240/a
http://www.thenewamerican.com/tna/1997/vo13no25/vo 13no25_alarmism.htm
Perhaps, should we enter a new ice age, the northern countries will want to reconsider this idea...
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As usual there is a better discussion on realclimate.org.
As I understand it the situation is that the mechanism proposed for sudden climate change by Broecker some 15 years ago (and exaggerated beyond recognition in a silly movie lately) shows some signs of actually occuring. New measurement expeditions have reinforced the evidence in this direction. Though the evidence isn't absolutely conclusive, it's starting to weigh in that direction and the new evidence makes the case stronger. There is well-understood physics at work, but it involves delicate small-scale structures that are hard to capture in global scale models.
Though most scientific opinion expects it won't be enough to trigger a European ice age (unlike the YD event some 11KA ago) it could lead to a great deal more climate variability in our lifetimes especially in Europe and the northern reaches of the Atlantic than has been captured in most climate models, and in the extreme it may even cool Europe a bit as the rest of us get hotter.
mt
Some people say that the real "global warming" problem has to do with increased energy output from the sun. Good luck stoping that one.
Magnetic Poles May Be About To Flip
Earth's Magnetic Field Weakens 10 Percent
The New York Times On Earth's Magnetic Flip-Flop
Since there's nothing I can do to prevent the change that's coming, I'm getting ready for it. The ride gets bumpier from here on out, until about 2011 or 2012, which is the end of a cycle in the Mayan calendar. As I understand it, their calendar cycles back to zero on December 21, 2012. (The universe has an "overflow bug" too!
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By Steve Connor, Science Editor The Independent, 10 February 2003 Generations of schoolchildren have been raised on the belief that the mild British winters and cool summers are due to the moderating influence of the Gulf Stream, a warm ocean current flowing from the Gulf of Mexico to the shores of western Europe. Without the Gulf Stream, our teachers told us, Britain's winters would be as cold and ice-bound as a frozen port in Newfoundland and its summers as hot and stuffy as a Moscow August. But the textbooks have got it wrong, according to scientists who have just finished a study of what makes Western Europe cool in summer and mild in winter. The scientists found that Britain's moderate climate is due not to the Gulf Stream, but to the Rocky Mountains in the western US 4,000 miles away. Using weather data gathered over the past 50 years and powerful computer models to describe how heat is shunted around the globe, they discovered that the contribution of the Gulf Stream was negligible compared with the influence of warm southerly winds originating in the Rockies. These winds, they said, played a big role in explaining why winters in Britain could be anything up to 15C or 20C warmer than the same latitude in eastern North America. "Belief in the benign role of the Gulf Stream is so widespread that is has become folklore," said Richard Seager, the scientist who led the study from the Lamont Doherty Earth Observatory at Columbia University in New York. The belief that the Gulf Stream is responsible for Britain's mild, maritime climate appears to have originated with the publication in 1856 of a book by Maurice Fontaine Maury, a lieutenant in the American Navy. "One of the benign offices of the Gulf Stream is to convey heat from the Gulf of Mexico, where otherwise it would become excessive, and to disperse it in regions beyond the Atlantic for the amelioration of the climates of the British Isles and of all Western Europe," Maury wrote. "This idea is one reason why so much climate research has been focused on the impact of changes in the circulation of the North Atlantic Ocean," Dr Seager said. Several recent studies, for instance, have suggested that global warming might slow down or even stop the Gulf Stream which carries energy equivalent to 27,000 times the total output of all of Britain's power stations so bringing a far more variable continental climate to Western Europe. Dr Seager's study, published in the current issue of the Quarterly Journal of the Royal Meteorological Society, suggests that the Gulf Stream accounts for no more than 10 per cent of the winter temperature differences between Britain and Newfoundland, Canada. The scientists found that the real reason for Britain's mild weather was twofold. First, there is a genuine maritime effect of being surrounded by a relatively warm body of water, but this has nothing to do with the Gulf Stream. Second, this maritime influence is bolstered by southwesterly winds bringing a warm air mass from the south. These winds would not blow if the Rockies did not exist, the researchers found. Even without the Gulf Stream, Britain would be bathed in prevailing westerly winds that bring in the warmth stored in the Atlantic Ocean. Water retains summer heat far longer than land, which is why the winter-summer difference in temperature is about 5ÂC over the North Atlantic and yet nearer 50ÂC at the same latitude in Siberia. Dr Seager said his study showed that this phenomenon which was independent of the Gulf Stream accounted for about half of the winter temperature difference between Britain and Newfoundland. The other half, he said, was due to the prevailing winds over the maritime regions of Western Europe--not westerlies, but from the southwest. Those south-westerlies brought additional heat to Western Europe. Their origins could be traced to a massive "meander" in the north-south wind patterns over North America, which was generated by the presence of the Rockies. "One such meander occurs east of the Rocky Mountains and brings cold air into eastern N
How was it "designed to economically punish the USA"? By requiring USA to cut down emissions? Guess what Einstein? It required EU (among others) to cut their emissions as well! In fact, the requirements were higher for EU than for USA! And there's few things to consider:
a) In Europe, power is generated relatively cleanly (nuclear etc.). Not so in USA
b) Cars in Europe are relatively environmentally-friendly, when compared to cars in USA
c) Industry in Europe (steel among others) had already spent lots of money modernizing their plants, making the more environmentally friendly.
d) People actually use mass-transportation in Europe, not so in USA.
What does all that mean? It means that USA could easily reach the requirements of the treaty by doing the stuff EU already did. EU could not, they would have to find other ways to cut their emissions, since all the easy things have already been done (not so in the USA).
Even simpler: EU worked hard to cut down emissions. Then they were told to cut their emissions by 9% (IIRC) more. USA did jack-shit to cut down their emissions, and then they were told to cut their emissions by 8% (again, IIRC). So it would be relatively easy for USA to cut their emissions, while it would be considerably harder for EU.
"Punishing the USA" my ass!
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77-23 in Senate and 296-133 in House is as one-sided as 100-0 or 99-1?? That's a clear majority, but not quite "one-sided."
The laws intent was to help rural people, as in farmers. However as with a horrid system of taxes that the US suffers from a loophole was found. The law did not originally specify what "types" of vehicles qualified for the discount. It merely stated over 6,000 pounds. This normally would have been the domain of vehicles used mostly on farms and some small businesses.
And thank you incompetent politicians who failed to write "trucks and agricultural machinery" into the law. That some people will use any tax loopholes they can has been known for decades, it should not come as a surprise anymore.
Now, what to do about it?
In the current system, the obvious step would be to elect better politicians in the hope of eventuaaly getting better laws. Of course, this requires smarter voters in the first place, but it would be the civilized and legal way.
If you like lynch mobs, you could also go after the people who exploit the loopholes. But that would be a real messy way, with a good chance of total anarchy breaking out.
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You are right that the direct energy of combustion would have only minimal effects (though we have used enough energy to seperate the fresh from the bracking water, if we were able to concentrate all the energy across time and space of human history into the North Atlantic in a single moment). All known oil reserves only add up to about 1 day's worth of sunlight.
However, greenhouse gases work by trapping natural heat, not through the energy of combustion. They work much like a catalyst, not getting used up in the process. Much like a blanket or a greenhouse is not consumed in keeping things warm, greenhouse gases do not get consumed in the process of warming Earth. The gas equivalent of a millimetre-thick dry-ice blanket around the Earth is about all it takes to cause substantial global warming. If you do the math, you'll find that the amount of CO2 we've spewed is several times larger than enough to account for the warming observed, and in fact, scientists are curious as to why there hasn't been more warming that has been observed. (current theories are that the ocean is acting as a buffer, both for CO2 and as a thermal buffer).