On Aug 4, 2009, at 1:44 PM, mix...@bigpond.com wrote:
In reply to Horace Heffner's message of Mon, 3 Aug 2009 21:11:31
-0800:
Hi,
[snip]
A shift of the current south toward Africa would necessarily also
mean that the
north east coast of the US would miss out, however that's unlikely
to have a
large effect on the passage past Florida. IOW at least some of the
energy being
tapped would still be available, and that's where this thread
started out.
If I'm not mistaken there is a sort of bottle-neck off the Florida
coast that
the current flows through. That is unlikely to change, though it's
direction
thereafter could change considerably.
There is debate among experts as to whether the thermohaline
circulation can shut down, and whether it can shut down quickly, as
it did in the two Dryas periods. See:
http://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation
Some experts think it can shut down fast due to global warming.
In any case as I noted: "There is evidence that a theorized Younger
Dryas impact event, 12,900 years ago in North America could have
initiated the Younger Dryas cooling and population bottleneck or near
extinction of the Clovis people.[13]" Clovis digs and finds extend
well into the South of the US, including Georgia and Florida.
If you look at the thermohaline circulation map in the above
reference you can see the the driving energy comes principally from
the north and south polar regions, and it is one large loop. The
energy to drive the half of the loop above the equator would be gone
if the north polar region lost all its down flow chimneys. I makes no
sense at all that the thermohaline circulation loop will move away
from Europe and not the US as well. Also, if the flow merely
declines, it will decline everywhere. The flow is a complete circuit.
In any case, I stick by my original statement, which take to be self
evident: "It [The Gulf Stream] may also permanently disappear too
fast to avoid the loss of power by other means." If we invest
billions in offshore turbines and the flow disappears or moves away
from the coast, we will be hard pressed to replace the renewable
energy source fast enough. If true to form, the experts and
politicians will probably waste five or ten years just arguing about
what is happening and if it is happening.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
