Yes. There appears to be a nonlinear system which governs the global
oceanic circulation and it can switch from one state to another in a decade
or so. There are some who are worried that we are about to see another
switch. Consider the following:
"With a flow equaling that of 100 Amazon Rivers, the conveyor delivers
enough heat to the North Atlantic's northern half to equal 25% of the solar
energy reaching the surface there. Off Labrador and north of Iceland,
frigid winds absorb that heat and carry it downwind, easing the chill on
Europe and adjacent lands by as much as 10o C."~Richard A. Kerr, "Warming's
Unpleasant Surprise: Shivering in the Greenhouse?" Science,
281(1998):156-158, p. 156
If you shut the current off or divert it, you will freeze Europe. The
above article is very good at explaining what some researchers are worrying
about.
>Is there an indication of a change in the angle of the "axle" of the earth?
Only on a long term basis, with slow rates of change.
> Is it true that the polarity of the earth changed? If so, how come, and
>does it involve climate change? What about the "Ice Age"?
As to different scenarios this is one I posted last August, but the
archives doesn't exist for that month so I can't point you to it. I will
repost it.
**old post**
For those of an environmental bent, here is grist for the mill. What is
the connection between the Aswan Dam on the Nile and the future land prices
in Canada? Give up?
Consider the consequences of the Aswan Dam and what it does for or to the
Mediterranean ocean. The Mediterranean Sea is a highly evaporative basin.
The river flow into the sea does not match the evaporation rate. This means
that the Atlantic ocean waters must flow into the Mediterranean to replace
the deficit. The water that enters the sea becomes saltier and denser as
evaporation takes place. This creates an extremely saline bottom water on
the Mediterranean ocean bottom. Johnson writes:
"If all the Nile flow entered the Mediterranean, the
hydrologic deficit would be approximately 31,000 m^3 s^-1,
estimated from Mediterranean outflow and inflow volumes and
salinities at Gibraltar, river discharges, and an assumed steady
state. A larger hydrologic deficit due to the loss of Nile River
discharge is the main difference between today and 120,000 years
B.P. in the chain of factors in Figure 2."~R. G. Johnson,
"Climate Control Requires a Dam at the Strait of Gibraltar," EOS,
Transactions, American Geophysical Union, July 1, 1997, p. 280
Combined with global warming, the Mediterranean bottom waters are becoming
more and more salty. Johnson continues
"The saline and initially warm Mediterranean outflow is about 0.8
X 10^6 m^3 s^-1. Leaving Gibraltar, the water sinks and mixes with
very cold water of the lower thermocline, moves northward, and
enters the northern gyre. As the water approaches the shallow
banks north and west of Ireland, it upwells.
"The cold core of the outflow water mixture probably reaches
the surface; it has a velocity as much as 0.01 m s-1 greater than
surrounding North Atlantic Drift water."~R. G. Johnson, "Climate
Control Requires a Dam at the Strait of Gibraltar," EOS,
Transactions, American Geophysical Union, July 1, 1997, p. 227
What this does is divert water from the Gulfstream and sends it north to
the Labrador Sea. One might thing that this would mean warm winters in
Canada. Apparently it doesn't. Over the next 100 years Johnson says the
following events will happen.
"The mixing time for an ideally mixed Mediterranean Sea (that is,
the time needed to attain 63% of a new higher steady-state
salinity after an abrupt reduction in fresh water input) is about
100 years. Consequently, most of the effect on northern North
Atlantic circulation caused by the 9% increase in the deficit
will be realized by the end of the next century as the salinity
rises and the Mediterranean outflow increases."~R. G. Johnson,
"Climate Control Requires a Dam at the Strait of Gibraltar," EOS,
Transactions, American Geophysical Union, July 1, 1997, p. 280
What will happen?
"If proportionality assumptions hold, 14% more warmer
surface water could enter the Labrador Sea with a corresponding
substitution of cold water entering the Nordic Seas. This
increase may initiate new glaciation for two reasons: the last
ice age was probably triggered by an inferred hydrologic deficit
equal to or less than that of today, and Canadian glacial
nucleation areas are now perilously close to the threshold for
new ice-sheet growth, as indicated by historic expansion of snow
fields on Baffin Island. Severe cooling in northern Europe and
new expansion of Baffin snow fields may occur within the next few
decades."~R. G. Johnson, "Climate Control Requires a Dam at the
Strait of Gibraltar," EOS, Transactions, American Geophysical
Union, July 1, 1997, p. 280
"Initiation of new ice sheet growth is of great concern
because the strong positive feedback of enhanced albedo and
heavier cloud cover, much like the effectiveness of cloudiness
over the Greenalnd Ice sheet today, might lock in the ice-age
growth mode despite CO2 warming. The ultimate consequence might
be a combination of two extremes. The strong CO2 warming of
lower-=latitude land and sea surfaces would nourish--be ever
stronger moisture advection--rapid expansion of ice sheets in
Canada and Eurasia."~R. G. Johnson, "Climate Control Requires a
Dam at the Strait of Gibraltar," EOS, Transactions, American
Geophysical Union, July 1, 1997, p. 280
Thus, northern Canada might not be the place for a long term investment.
Bring on the glaciers.
glenn
Adam, Apes and Anthropology
Foundation, Fall and Flood
& lots of creation/evolution information
http://www.isource.net/~grmorton/dmd.htm