oh well the warm weather was nice while it lasted.
So the Uk can now look forward to temperatures as warm as Newfoundland as it sits on the same line of lattitude...or is it longitude?


http://www.newscientist.com/article.ns?id=dn8398

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.

The slow-down, which has long been predicted as a possible consequence of global warming, will give renewed urgency to intergovernmental talks in Montreal, Canada, this week on a successor to the Kyoto Protocol.
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Harry Bryden at the Southampton Oceanography Centre in the UK, whose group carried out the analysis, says he is not yet sure if the change is temporary or signals a long-term trend. "We don’t want to say the circulation will shut down," he told New Scientist. "But we are nervous about our findings. They have come as quite a surprise."
No one-off

The North Atlantic is dominated by the Gulf Stream – currents that bring warm water north from the tropics. At around 40° north – the latitude of Portugal and New York – the current divides. Some water heads southwards in a surface current known as the subtropical gyre, while the rest continues north, leading to warming winds that raise European temperatures by 5°C to 10°C.

But when Bryden’s team measured north-south heat flow last year, using a set of instruments strung across the Atlantic from the Canary Islands to the Bahamas, they found that the division of the waters appeared to have changed since previous surveys in 1957, 1981 and 1992. From the amount of water in the subtropical gyre and the flow southwards at depth, they calculate that the quantity of warm water flowing north had fallen by around 30%.

When Bryden added previously unanalysed data – collected in the same region by the US government’s National Oceanic and Atmospheric Administration – he found a similar pattern. This suggests that his 2004 measurements are not a one-off, and that most of the slow-down happened between 1992 and 1998.

The changes are too big to be explained by chance, co-author Stuart Cunningham told New Scientist from a research ship off the Canary Islands, where he is collecting more data. "We think the findings are robust."
Hot and cold

But Richard Wood, chief oceanographer at the UK Met Office’s Hadley Centre for climate research in Exeter, says the Southampton team's findings leave a lot unexplained. The changes are so big they should have cut oceanic heating of Europe by about one-fifth – enough to cool the British Isles by 1°C and Scandinavia by 2°C. "We haven’t seen it yet," he points out.

Though unseasonably cold weather last month briefly blanketed parts of the UK in snow, average European temperatures have been rising, Wood says. Measurements of surface temperatures in the North Atlantic indicate a strong warming trend during the 1990s, which seems now to have halted.

Bryden speculates that the warming may have been part of a global temperature increase brought about by man-made greenhouse warming, and that this is now being counteracted by a decrease in the northward flow of warm water.

After warming Europe, this flow comes to a halt in the waters off Greenland, sinks to the ocean floor and returns south. The water arriving from the south is already more saline and so more dense than Arctic seas, and is made more so as ice forms.
Predicted shutdown

But Bryden’s study has revealed that while one area of sinking water, on the Canadian side of Greenland, still seems to be functioning as normal, a second area on the European side has partially shut down and is sending only half as much deep water south as before. The two southward flows can be distinguished because they travel at different depths.

Nobody is clear on what has gone wrong. Suggestions for blame include the melting of sea ice or increased flow from Siberian rivers into the Arctic. Both would load fresh water into the surface ocean, making it less dense and so preventing it from sinking, which in turn would slow the flow of tropical water from the south. And either could be triggered by man-made climate change. Some climate models predict that global warming could lead to such a shutdown later this century.

The last shutdown, which prompted a temperature drop of 5°C to 10°C in western Europe, was probably at the end of the last ice age, 12,000 years ago. There may also have been a slowing of Atlantic circulation during the Little Ice Age, which lasted sporadically from 1300 to about 1850 and created temperatures low enough to freeze the River Thames in London.

Journal reference: Nature (vol 655, p 438).

That is a scary prospect.

Southampton Oceanography Centre is a well funded, well equipt research center, so this probably ISN'T junk science.

Somebody stop Greenland from melting so fast, pls.

This is serious ... the one that some of us have been watching for. There was a simulation study using HadCM3 which I posted in this site a few months ago. The implications of a major fuck-up in the thermohaline currents are truly shocking.
The multimedia version : http://www.whoi.edu/institutes/occi/cur ... e_wef.html
and the simulation using HadCM3 ...
http://www.peakoil.com/post147387.html#147387
IT will not be just Europe which will be affected .....
Did I hear any objections to nuclear and offshore wind-farms and the need to park the stupid SUV FOR GOOD?

A 30% reduction is pretty darn serious...if this turns out to be accurate, the world should start feeling the effects shortly...not only will europe get colder but the tropics will start heating up...

I wish we didn't hunt all those animals to extinction in the last ice age.

Torjus Gaaren

this has happened before..? it will happen again...

Apparently the thermohaline system has 3 different operating regions.
It has shut down in the past and it will shut down again in the future.
But it seems that this slowing down is "man-made" i.e. due to global warming. In a scenario where the CO2 rises to x4 pre Industrial age levels (now it is 1.3 x) the GS shuts down for about 1000 years me thinks.
The tropics heat up, Europe cools down ( a lot) and the Midwest has a drop (but small in temperature). Throughout the world precipitations drops way down. No rain, plenty of ice ....
It was this aspect of CC/GW which made me hysterical about nuclear .....
If we are able to cap the peak of Co2 to x2 pre-industrial level then in the worst case we will have to deal with 30-70 years of cooling (in case GS shuts down). The South America and Asia will be hit hard due to the decrease of precipitation ... we might have to end up in wide scale sea water desalination just to ensure that we maintain part of the original ecosystem in SA.
I really do not see many survivalists and manure powered utopias surviving this without electricity generation at a scale that is manageable by renewables ......
Powerdown just to renewables will result in an exponential growth in the number of ghosts

I understand from Discovery Channel (I know, I know: not a news source) that there are a number of respectable scientists now claiming that northern Europe owes its mild climate not so much to the gulf stream as to warm air currents that sweep up from the south. Courtesy, strangely enough, of the Rocky Mountains here in the US.

But the show made no effort to deny that a failure of the trans-oceanic conveyor belt would mean catastrophic effects on a global scale. This is the great evener that keeps the climate friendly for us human types. If it goes, it won't just be "uh-oh, the British Isles are going to freeze over." The effects will be global and severe. The mini-ice age wreaked enough havoc on the modern world. How about a real ice age?

Perfect Storm. Get ready.

BBC News coverage of topic

This BBC article has more information

here

Take home points from the paper (has nice figures BTW, you can take a peak if you do not read the whole story)
The strength of the
North Atlantic overturning reduces to near zero very quickly, and then recovers to its original strength over a period of ca. 120 years (the recovery process is discussed . The atmosphere responds quickly to the change in ocean circulation. A cooling of the Northern Hemisphere is rapidly established (figure 1a), which is strongest over and adjacent to the North Atlantic.
....Over the first three decades the response develops to include a warming in the Southern Hemisphere.....
Over the UK the mean cooling is 3–5 ◦C in the first decade, and
2–3 ◦C in the third decade. The cooling is fairly uniform through the seasons. To put such a cooling in context, a typical decadal mean cooling during the ‘Little Ice Age’ period of the late seventeenth and eighteenth centuries, as seen in the Central England temperature record (Parker et al . 1992), is of the order of 0.5 ◦C, and the coldest individual year in the record (which goes back to 1659) was 1740, with an anomaly of −2.5 ◦C (anomalies are taken relative to the 1961–1990 mean).
...As a response to the general cooling of the Northern Hemisphere, there is
a widespread reduction in both surface evaporation and precipitation there....
The combined temperature and hydrological changes would be expected to have a significant impact on vegetation and agriculture. While these effects are not fully modelled here, the model does estimate the change in net primary productivity by land vegetation, on the assumption that the current mix of vegetation types is maintained. This is suggestive of the magnitude of changes that could be expected. There is reduction of 12% in the primary productivity of the Northern Hemisphere as a whole, with larger regional changes: −16% in Europe, −36% in the Indian subcontinent and −109% in Central America (the latter implying that the current
mix of vegetation types is unsustainable).

Bye bye Mexico, Venezuala, Cuba, Panama .... no trees to hug
The influence of the CO2 level when the shutdown occurs:
In the 2 × CO2 run, the overturning weakens, but starts to recover ca. 70 years after stabilization, and returns to its original value by 400 years after stabilization.
In the 4 × CO2 case, the overturning becomes very weak, and remains weak for over 1000 years after stabilization. Then, there is a fairly rapid recovery to pre-industrial values over 100–200 years.

(2x CO2 = twice the preindustrial CO2 level, 4xCO2 = four times the pre-industrial level, currently we are at 1.3 x CO2 preindustrial levels)
Of course they add the following:
Based on the evidence above there are reasonable grounds to speculate that a rapid or irreversible shutdown of the THC over the next century is a rather low probability event. Nonetheless, given the evidence from models that there are probably thresholds in the system, and the fact that we are clearly not yet at a stage where the that a spontaneous ‘flip’ is unlikely in models are good enough to make confident, quantitative statements about THC changes, the possibility needs to be taken seriously....
Following several decades of global warming, such a shutdown
would return northwestern Europe in particular to a climate that was substantially colder than pre-industrial
Cold and dry = terrestrial primary productivity is reduced by 20% (20% less plant growth)
BTW predictions for the East part of NA are similar; the weather will be much colder and severe drought will occur throughout the continent, however temperature will go down by -6 degrees and drought will be more severe in certain parts of the continent (midwest might see an actual increase 3 decades post the event).
Any comments?

Can you imagine the amt of energy (increase from current levels) that N Hemisphere will have to burn to keep WARM! Europe will be importing trees from Canada/South America just to keep warm--along with whatever else they can get their hands on to.

It is not unreasonable to ask if the warming Gulf of Mexico and the resulting hurricanes are not related to this disruption of the North Atlantic Conveyor.

There was an item on Channel 4 news here in the UK tonight. My doomerosity blipped upwards sharply.

If this is correct, and we will have to wait for more information, it seems there is no end to out f*cking the planet up.

ahhhhhhh shit.....

Ok guys you convinced me , THE BRITS ARE ALL GONNA DIE!!!! (and soon.... )

Suprised Leaf hasn't joined in this thread to stick the boot in!!!

I think that's a very fair question Pstarr...maybe we're already seeing some of the effects.