A bolide did it! No... not really. (1)

[MariusRomanus@aol.com]

http://www.cardiff.ac.uk/news/03-04/040204.html

Astronomers unravel secrets of sixth-century cometâââ 

Let me get this straightâ Apparently, a bolt from the Far Beyond is the only 
thing that can cause atmospheric cooling, especially within a relatively rapid 
time frame. Itâs flashy... itâs sexyâ itâs radâ. itâs cool (pun 
intended). Me? I think itâs nothing but a cheap thrill from riding Space 
Mountain at Disney Land.

Forget for a second what we know about volcanoes and their effects on global 
climate. I doubt if Pinatuboâs ash cloud is even the size of a spec of dust 
in the memory anymore. Not as endearing as "Death From Above" I suppose. While 
we are at it, put thoughts about CO2 on hold as well. Instead, focus on a lil 
something called the Thermohaline Circulation, also known as the Meridional 
Overturning Circulation. Oh how we easily forget about the profound influence 
exerted on climate by 70% of the earthâs surface. Unlike a bolide (the 
Tunguska air burst being the only exception), weâve actually experienced and 
also have records of what happens when this oceanic heat transport goes to pot. 
Anyone remember that famous painting by Emmaneul Gottlieb Leutze of George 
Washington Crossing the Delaware River on Christmas Eve of 1776?  Most people 
think those guys in the boat are rowing. Look again. They are actually using 
their oars to push blocks of ice out of the way. In fact, the!
  l!
ead oarsman is actually beating the frozen river with his boot. How about the 
16th century painter Pieter Bruegel the Elder and his paintings of an 
ice-choked Europe? Ever see his 1565 painting called âHunters in the Snowâ? 
Whatâs depicted there isnât the temperate European landscape we all know 
today. Events such as these were commonplace during the period known as the 
Little Ice Age, which occurred in the years spanning roughly 1200 to 1800 A.D. 
(Start and end period estimates vary from 1100 to 1900 respectively), and is 
believed to have been caused by a disruption of the Thermohaline Circulation of 
the North Atlantic. The huge ice-sheet of glaciers like those of 12,000 years 
ago that covered the Northern Hemisphere werenât required for disaster across 
Europe. Agriculture all but ceased to exist. Famine and disease were rampant. 
Finland itself lost perhaps a third of its population (See the book entitled 
âThe Little Ice Ageâ, by anthropology professor Brian F!
 ag!
an of UC at Santa Barbara, published in 2000). (Something!
 else of 
interest is that the Little Ice Age happens to coincide with the reduced solar 
activity of the Maunder and Sporer solar minima.)

But you know what? The Little Ice Age wasnât just a European thing. Its 
effects were global in their extent. But, itâs a time of cooling that took 
place long before the 1300âs that is the topic of that article. Itâs all 
about The Dark Ages baby.

Ever hear of the Dark Ages Cold Period? Well, if you havenât, this is 
basically what the authors of that article are referring too. Unfortunately for 
them, itâs my opinion that they are being very misleading about not only this 
periodâs extent and breadth, but of the climate fluctuations that occurred 
both before and after it. Preceding the Dark Ages Cold Period, which actually 
lasted from roughly 100 B.C. to 700 A.D., is an interval known as the Roman 
Warm Period, which spanned a time frame encompassing roughly 900 to 100 B.C. 
After the Dark Ages Cold Period, followed what is known as the Medieval Warm 
Period, which lasted from approximately 700 to 1300 A.D. Finally we come to the 
Little Ice Age, which lasted to roughly 1900 A.D.

There has been such an accumulation of data in support of such climate 
fluctuations, that itâs completely infeasible for me to go through all of it 
here. Instead, take a gander at 
http://www.co2science.org/subject/d/summaries/rwpdacp.htm. The website, though 
with the purpose of taking the focus off of modern day global warming, does 
give very good summaries of the most important articles pertinent to the 
climate fluctuations mentioned above. Check it out if you want the dirty 
details.

Before I proceed any further, who wants to tell me that every single one of 
those climate fluctuations were due to a bolide? Anyone? All the signatures are 
there right? Gettin hot, then gettin cold. A hothouse then the nuclear winter. 
I've read over and over that those be telltale signs of an impact. No iridium 
layer(s) found as of yet, but we can always work around that inconvenience 
right? Let's give the space bullets the benefit of the doubt and call them 
typical carbonaceous condrites (comet pieces), which just happen to be low in 
their iridium content. To my knowledge, we also lack impact structures that 
correspond to these climate changes, so we are unable to say âLook! We have a 
crater! Obviously it caused the climate change!â. Therefore, how about 
multiple Tunguskas says I. Problem solved...

OK... sarcasm aside... What we have here isn't due to any bolide; It is the 
manifestation of a naturally induced millennial-scale cycle of climate, which 
just happens to be controlled by the transport of heat from low latitudes to 
higher latitudes via a circulation called the North Atlantic Deep Water, itself 
born from the Thermohaline Circulation.

On to post number 2......