This is big news. I posted four years ago now that the mostlikely explanation for the apparent changes in the climate and in particular,the specific erosion of sea ice in the Arctic was a specific change in thetotal heat been delivered by the Gulf Stream which we may simply label deltaH. Simply applying a delta H since theseventies perfectly explains our observations since then and led me to predicta possible pending complete breakup of the Arctic sea ice as early as 2012 andinevitably soon thereafter.
We continue to have warmer thannormal Arctic conditions. However theNavy is claiming that the ice has finally began to thicken again over the pasttwo years. So far it is the onlyavailable evidence that the warming delta H may have ended. If it has ended, then an Arctic breakup isaborted.
This report tells us that for thepast forty years that the Labrador Current was much weaker. This means several things.
1 A strong current mixed vigorously with the Gulf Stream , partially cooling it. This was hugely reduced when the currentabated.
2 A warmer Gulf Stream carried more heat or delta H as aconsequence into the Arctic and wasinstrumental in eroding the sea ice.
3 An offsetting counter flow somewhere else took over andthis had little effect on the Gulf Stream . The net effect was to modestly strengthen theGulf Stream .
Now the geological record showsus that the Gulf Stream has been much warmerby a couple of degrees and that long cyclic warm eras are common. If my own interpretation holds up, we areentering a prolonged warm period in Europe similar to the Medieval optimum aspart of an apparent thousand year cycle that I have been able to identify on apreliminary basis over 5,000 years.
I would be quite surprised if theimplied claim of no similar events for 1800 years were to hold up. Right now we have a well positioned coralreef able to act as a monitor. Therewill be others and we may be able to go further with this form of testing.
ATLANTIC CIRCULATION ON THEFASTTRACK FOR CHANGE
Analysis by Tim Wall
Tue Jan 4, 2011 05:55 PM ET
Bell-bottom jeans, Abba, and the Labrador Current-- one of the three is not making a retro comeback. Temperature-tracking coralreefs indicate that the circulation of water in the Atlantic Ocean has changed dramatically since the 1970's.
That could be part of the reason areas in thenorthern hemisphere have had harsh winter storms and summer droughts sayresearchers.
The evidence for changing currents comes fromancient gorgonian coral reefs growingoff the coast of Nova Scotia Switzerland , Canada ,and the United States
Like most organisms, corals are what they eatand changes in their diet are recorded in the reef structure.
The Canadian corals showed that the cold,south-bound Labrador current islosing ground to the warm, north-bound Gulf Stream current. The corals of the deepnorth Atlantic have been feasting onnutrient-rich warm water since the 1970's.
The researchers looked at the concentrations of acertain isotope of nitrogen, called delta15. Different concentrations of the isotope allow scientists to trace acreature's food sources.
The levels the researchers found in the NovaScotian coral indicated the coral had been feeding heavily on nutrients broughtnorth from the subtropical regions for approximately 40 years.
The coral had been feeding primarily onsubarctic nutrients for the previous 1800 years.
That abrupt change in food sources caused bychanges in currents coincides closely with the onset of observable changes inEarth's climate caused by industrialization.
"The researchers suspect there is a directconnection between the changes in oceanic currents in the North Atlantic andglobal warming caused by human activities," said one of the participatinginstitutions, the Swiss Federal Institute of Aquatic Sciences andTechnology in a statement to the Associated Foreign Press.
The coral reef research was published recently inthe Proceedings of the National Academyof Sciences.
Recent heavy snowfalls and harsh winter stormsalong with droughts and heat waves in the summer, could be explained by achanges in the circulation of the Atlantic 'swater, say climate researchers. A 2004 paper by NASA explainedthe possibility of melting arctic sea ice triggering colder weather in Europeand North America .
As my colleague, Mr. Cox, pointed out in theabove blog post, the term global warming is a misnomer in many senses. Humanityfaces global climate destabilization. The weather patterns our agriculture andindustry have adapted to over the centuries are changing rapidly.
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