If you believe the latest calculations, the giant water circulation in the Atlantic ocean may stop for 300 years, if the concentration of CO₂ in the atmosphere will double.
The idea that the Gulf stream may stop, led to the emergence of horrible fantasies on the silver screen, though, and found great understanding among scientists.
But a recent report published in the renowned journal Science, suggests that climate researchers have underestimated the possibility of collapse.
Wei Liu and fellow researchers at SCRIPPS institution of Oceanography (Scripps institute) has produced some calculations that say that the Gulf stream may cease to exist if the climate will become warmer, and that means that warmer ocean water may cease to flow in colder areas.
Scientists claim that this may result in a significant cooling of the North Atlantic and adjacent areas.
“If this is true, the situation for Norway will change radically,” says Rasmus Benestad (Rasmus Benestad) of the Meteorological Institute, Norwegian researcher working on issues of climate, acquainted in more detail with the material in the journal Science.
According to the new report, the Gulf stream may be one-third weaker for a hundred years, and two centuries later stop its existence.
NB! Note that the concept of “Gulf stream” initially does not mean the ocean current directly off the coast of Norway. Get the facts!
Many names of the Gulf stream create confusion
When it comes to the Gulf stream, should be especially cautious. Actually we are talking about three different systems, and only one of them is a real Gulf stream:
AMOS/Circulation in the Atlantic ocean: a Grand system of currents in the Atlantic ocean, which carries water from the equator towards the poles and cold water back to the equator.
Gol: Can be seen as an offshoot of AMOS, carrying warm water northward. Divided in two, most of the water goes to the East or North-East, to what is called the North Atlantic current.
The Norwegian Atlantic current: an offshoot of the North Atlantic current, which continues into the Norwegian sea and then goes North along the coast of Norway. The name of the Gulf stream often incorrectly used in relation to the Norwegian Atlantic current. It is also sometimes called the “Norwegian Gulf stream.”
Changes in the “salt budget”
The new study differs from previous studies of the Gulf stream the fact that different estimates the salt content in the ocean.
Traditionally it was believed that the Gulf stream will remain quite stable despite the warming climate, and the weakening, and then moderate, can be “only” in the next century.
Many scientists believe that the predictions were not correct, the new calculations show that the ocean current in the Atlantic ocean is much more sensitive to changes in temperature and salt content, than previously thought.
Wei Liu and colleagues say that the changes have already begun. Circulation in the Atlantic ocean has become weaker in the last century, although full confidence in this and no.
“Vicious circle”, which does not stop
What can happen with the Gulf stream, is a classic example of a turning point in the climate system, writes the German climate researcher Stefan Rahmstorf (Stefan Rahmstorf) from the Potsdam Institute in comments to the article in the journal Science.
If the current is weakened, reduced flow of salt water, which in turn will help to ensure that the water to settle will be less. And thus, the motor ocean currents will become less powerful.
“This is a critical point where it becomes a vicious circle that cannot be stopped. But it remains unclear where this critical point,” says Rahmstorf.
Two years ago, Rahmstorf himself published a rather controversial report, which stated that the Atlantic meridional circulation (AMOS) will be much weaker.
“Significant implications for Norway”
If the results of a new study will receive support, it may mean that you have to make changes in the calculations regarding the climate of Norway in the future, says Rasmus “Benestad” from the Meteorological Institute.
“This could have major consequences for Norway. The forecast for the next 50 years may change.”
If the heat transfer in the ocean will change, countries such as Norway and England in the future may become colder than say the current forecasts.
“What is happening with the Gulf stream, can counteract global warming. Maybe the climate for some time will be stable? In this case, we’re lucky,” says “Benestad”, which explains that the effects of the weakening of the Gulf stream primarily visible in parts of the globe.
He adds that another consequence will be the possible change of the usual routes of storms off the coast of Norway.
He sees no signs of abating currents off the Norwegian coast
Oceanographer Svein Osterhus (Svein Østerhus) of Bergen Uni Research does not consider the situation as dramatic.
Since 1965, oceanographers from Bergen are the measurements of that branch of the Gulf stream that passes along the Norwegian coast. In the language of professionals is called the Norwegian Atlantic current.
“We have not seen any weakening of the Norwegian Atlantic current. On the contrary, there is a tendency to its strengthening,” says Esterhaus.
It is possible that the coast of Norway ocean currents may continue to exist as before, even if the large-scale circulation in the South Atlantic ocean becomes weaker.
“These are two factors that on the one hand interconnected, and on the other are independent of each other.”
“Others also need to continue this research”
However, Osterhus seriously a new report.
“This is such a serious issues, in particular, due to the melting of ice in Greenland, which is the idea that in the future may weaken the Gulf stream, including off the coast of Norway, does not seem unnatural”.
Now other researchers have to decide how they will trust the findings of the study Wei Liu and Ko.
“My opinion is that their results have a right to exist. But it is possible that they made some mistakes, so others to verify these results,” says Rasmus “Benestad”.
Stefan Rahmstorf agree with him.
“I hope that this sinister conclusion will inspire as many groups of scientists to continue research”.
