Weakening of Gulf Stream
 

I don't know how much weight to give this and can't find much more about it other than thoughts that it might happen in some sort of doomsday scenario. If this is happening to the extent described we've got serious potentials for world wide weather change of an extreme nature.
Alarm over dramatic weakening of Gulf Stream

""· Slowing of current by a third in 12 years could bring more extreme weather
· Temperatures in Britain likely to drop by one degree in next decade

Ian Sample, science correspondent
Thursday December 1, 2005
The Guardian


The powerful ocean current that bathes Britain and northern Europe in warm waters from the tropics has weakened dramatically in recent years, a consequence of global warming that could trigger more severe winters and cooler summers across the region, scientists warn today.
Researchers on a scientific expedition in the Atlantic Ocean measured the strength of the current between Africa and the east coast of America and found that the circulation has slowed by 30% since a previous expedition 12 years ago.

The current, which drives the Gulf Stream, delivers the equivalent of 1m power stations-worth of energy to northern Europe, propping up temperatures by 10C in some regions. The researchers found that the circulation has weakened by 6m tonnes of water a second. Previous expeditions to check the current flow in 1957, 1981 and 1992 found only minor changes in its strength, although a slowing was picked up in a further expedition in 1998. The decline prompted the scientists to set up a £4.8m network of moored instruments in the Atlantic to monitor changes in the current continuously.""


Read the whole article here

The EU will try to blame it on us somehow.....give them time.

I just wish someone could 'splain to me how global warming causes severe winters and cooler summers. I may not know everything, but I'm pretty certain it can't get both hotter and cooler simultaneously.

Oh trust me when they have a agenda to push they would claim excessive rain is a sure sign of a coming drought.

If I've got it right, the article is saying that warming melts the polar regions and adds more fresh water and doesn't allow the Gulf Stream to sink in the north as fast. This intern slows the current that warms Europe. What I'm trying to find out is if it is really happening to the degree they're talking about.
With all the explanations for the severe weather over the last few years I've heard this Gulf Stream bit hasn't been mentioned as more than a future potential that could really put things into a mess.
What's truly amazing is that this has quickly turned into this "stuck on stupid" left/right nonsense. There is nothing political about this. No wonder so many have left this board.

I've yet to see an enviromentalist that wasn't pushing some political agenda........sad but true...as it taints their credibility among many, on issues they may actually have a valid point on....


Boy who cried wolf syndrome.....

Who's the environmentalist? If you mean me, and in some ways I certainly am, I'm not advancing any agenda - other than preparation. I think a tide has turned, and human activity may be the straw that broke the Camel's back, but that's like looking back in time - I like to look forward.

no not you....but the people pushing the global warming thing....the spotted owl thing....the Kangaroo rat thing....decades of this that or the other thing makes me want to see unrefutible evidence to back anything they say....

Like I said the Boy who dried wolf story applies to them...

My question is, can any man understand the cause of these events?

Certainly not at this point. We can wrap our brains around isolated local phenomenon to some extent, but the global stuff -- forget about it. Our understanding of the workings of Earth's planetary core is startlingly vague. Without that basic grasp of our foundation, how can we do anything but speculate about global surface events?

And that's another reason why we need in-depth studies and co-operations from the global scientic communities. We cannot carry the whole burden, nor can we afford to. This is ultimately affecting the survival of every living creatures on the planet.

And I truely don't believe there is one country to blame, as much as people like to blame it all on us. So let's not try to make this as a political argument.

Wurd.

Response from resident wacko environmentalist follows.

First, we have to separate two ways that science views the world: Observational-correlative and causational-experimental.

From grade school onward we tend to focus on the causational-experimental as the 'proper' role of science. This is the labcoats, test tubes, and rats type science. It's where you hold many factors constant and only allow a few parameters to vary then you note the response. There is a direct cause-effect relationship. This is reductionary and mechanistic. It is the most reliable method of science possible. It builds bridges, spacecraft, stents, antibiotics, televisions and nuclear bombs.

The second is observational correlative. Charles Darwin would be an extreme example of that method. He painstakingly observed natures variations in organisms and reasoned relationships between differences and environmental factors to derive his theory of evolution. Evolution, cosmology, psychology, sociology, and anthropology are all examples of observational-correlative science.

Most sciences can be viewed using both paradigms. In fact, both paradigms are often used to address the same problem. They compliment each other.

In the weather sciences these two approaches can be used to describe and predict future events. A combination of the methodologies provides people with 5-day forecasts. Your local weather woman uses a large bluescreened map to demonstrate the mass flow of patterns while behind teh scenes she may have run a model or used models provided by consultants. These models are based on physics--the prince of causative science.

Climate is like weather but looks at long term trends rather than short term events. The step from weather forecasting to climatological modeling is huge. But the two science paradigms are still at play.

Climatological studies have models that are statistically based, observational and correlative. They also have models that are statistically validated but physical science based. Let's call the first kind (stat/obs/corr) a statistical model and the other model we'll call a physical model, though both share attributes and methods of the other and advances in either advance both.

The statistical model uses patterns of past occurences and present data to extrapolate future trends. Data comes from coral growth rings, ice depositional patterns, tree rings, stratigraphic layering, isotopic ratios and other things. These factors vary according local weather conditions. By gathering data world-wide scientists can remove local phenomena and look at base trends. As more data is gathered the model gets refined and improved.

The physical model uses knowledge of atmospheric chemistry and physics to derive extrapolations.

Both models use hindcasting to help gain confidence in the model. They will "predict" what the climate should look like at some historical date and then test the model by evaluating physical evidence.

The link between climatology and ocean circulation has long been known (observationally) but has only recently been attacked by physical science. The linkage is not strong for any given moment of time but it is pretty strong for long term trends.

The temperature difference between poles and equator causes a difference in salinity. Also, the temperature difference that varies with depth affects the salinities. The dissociation constants of salts are directly temperature dependent. Also, the density of water varies with temperature. Dense, cold, salty water is heavy.

Whenever there is a temperature difference in the climate and on the ocean there is a potential for currents, both atmospheric and oceanic. The linkage is real.

However, this particular model is data-sparse. There are very few data sets of real measurements of the ocean that are sufficiently comprehensive to provide reliable model inputs. So the model spits out scary information but it is not well founded.

As an aside, the evidence for a global warming trend is far richer. There is ample, compelling evidence that serious, large changes in temperature are underway. What is less well known is the degree to which these changes maybe anthropogenic and also the precision of the model output.

Bot

Gort.

Bot,
Well written.