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08/08/2002
Cold Weather Ahead?
Mea culpa. I goofed. If you read last week''s column before 2:30
PM on August 3rd, you found a statement that lithium iodide was
being sold or distributed to counter the effects of any radioactive
iodine released in a nuclear accident or terrorist attack. My
brother Conrad, an expert in the field of radiation damage to us
humans, called my attention to the fact that the compound is
potassium iodide, not lithium iodide. Thank you, Conrad. What
disturbs me most is that, prior to writing the column, I had
received many e-mail solicitations urging me to purchase
potassium iodide as insurance against a nuclear disaster. Could it
be the stifling heat or simply senile dementia that addled my
brain? I prefer to think it was the heat.
We''re inclined these days to blame lots of things on the heat
generated by global warming. The existence of global warming
is becoming more and more an accepted fact in the scientific
community and, more reluctantly, among our political leaders. Is
it already too late to take remedial measures to slow or halt the
warming trend? With the temperature outside hovering near 100
degrees Fahrenheit, I was startled to come across an article
suggesting that we may very shortly enter a new ice age. Even
more startling, the unlikely culprit is global warming!
The article, "The New Ice Age", is by Brad Lemley in the
September issue of Discover magazine. I also found some
informative articles on the most recent ice age by Scott Mandia,
a professor at Suffolk County Community College in New York,
on the Web site ww2.sunysuffolk.edu. That ice age was not like
the big one of some 12,000 years ago during which much of the
Northern Hemisphere was covered with the mother of all ice
sheets. I''m referring here to the so-called Little Ice Age that had
devastating effects in Europe as recently as the 1800s.
The 300-year Little Ice Age spanned the period from 1560 to
1850 and spawned famines, floods, killer storms and other tragic
events. For example, the cool, wet summers apparently
promoted the growth of various forms of fungus in stored grain.
One of these, ergot blight, causes a disease known as ergotism,
also known as St. Anthony''s fire. Sometimes affecting whole
villages, the disease caused convulsions, hallucinations and
gangrene. Ergot blight has even been suggested as a cause of the
Salem witchcraft hysteria in Massachusetts. Surprisingly, a
disease normally found in the tropics, malaria, was a major cause
of death in Chaucer''s and Shakespeare''s times in parts of
England. If you see the term "ague" in their writings that was the
term for malaria in those days. Ague did in Oliver Cromwell in
1658, one of the coldest years of the Little Ice Age. Apparently,
those cool, wet summers also allowed the mosquitoes that spread
malaria to flourish.
Some storms and floods were so severe that more than a hundred
thousand people would die in a single storm. Malnutrition,
resulting from the cold weather''s influence on agriculture and the
resulting poor crop yields, is thought to have caused the
malnourished to have compromised immune systems. With
limited immunity, diseases such as the Bubonic Plaque may have
caused more deaths than they would have in normal times. All in
all, it seems prudent to pay attention to the possibility that a little
ice age is just around the corner. You might say, "Come on, it
won''t happen overnight and, besides, we''re smarter than people
were in those days and we should be able to adjust." Would you
be a bit more concerned if an ice age was only ten years away?!
That very possibility has been posed by workers at the Woods
Hole Oceanographic Institution on Cape Cod in Massachusetts
and is the subject of Lemley''s article. I''ve seen quite a number of
articles over the past decade reporting new data on climate
histories all over the world. The data range from ice cores in
Greenland to cores taken from the bottom of the oceans to
analyses of tree rings from very old trees. The startling
conclusion from many of these studies is that the climate can turn
on a dime, geologically speaking. Drastic climate changes have
occurred very quickly, with little or no warning.
Take that famous painting of George Washington and his troops
crossing the Delaware River in the winter of 1776. Woods
Hole''s William Curry points out that those troops aren''t rowing
but are pushing away the ice from the boats. Curry, who lived in
Philadelphia, not far from the spot depicted in the painting, says
nothing like this is seen on the Delaware these days. Washington
crossed the Delaware during the Little Ice Age. While Europe
suffered the brunt of that age, it apparently was colder here also.
What caused that and other prolonged and suddenly appearing
cold periods? Proposed causes include variations in the output of
energy from our Sun or volcanic eruptions. Another factor that
may play a role is the earth''s albedo, that is, its reflectivity. If a
cooling trend leads to more of the earth being covered with snow
and ice, that snow and ice reflect more of the sun''s energy back
to space. This would cool the earth down further and more
snow/ice cover would result in more cooling etc., etc. Volcanic
eruptions can certainly influence the temperature over wide
areas. Witness the cooling that resulted for a couple of years
after Mount Pinatubo in the Philippines erupted a decade ago.
Recorded sunspot activity has been correlated with solar energy
output; some data suggest a correlation of the sunspot activity
with cold periods.
But what prompts Terrence Joyce of Woods Hole to worry that a
little ice age, or at least a major cooling trend, could be only 10
years away? As you might expect from an oceanographic
institution, the Woods Hole researchers are concerned about
another factor - ocean currents. Specifically, they talk about the
"thermohaline circulation" and the "Great Ocean Conveyor". The
latter is the huge global current pattern that carries cold deep
water from the North Atlantic Ocean around the globe to the
Indian and Pacific Oceans, where it rises and returns as warm
surface water all the way back to the North Atlantic.
We call the section of that warm current skirting the East Coast
of the U.S. the Gulf Stream. As it flows north, the Gulf Stream
gives up its heat along the way. As it cools down, the water
becomes denser and, in the upper reaches of the North Atlantic,
sinks down a mile or more into the depths of the ocean. This is
called the thermohaline circulation. After sinking down, the cold
water begins its journey down to the region of Antarctica and
over to the Pacific Ocean as part of the Global Ocean Conveyer.
So, what''s the problem? Over the past three decades, large
"rivers" of freshwater have poured into the North Atlantic. The
suspected cause of this sudden inflow of freshwater is melting of
Arctic icecaps due to global warming. Why worry about it? This mass
of freshwater is comparable to a huge thermal blanket that makes
it harder for the cooled Gulf Stream water to sink. The concern
is this freshwater could (a) shift the course of the Gulf Stream
southward, or (b) even worse, shut down the thermohaline
circulation completely.
Either scenario means trouble. The Woods Hole researchers
believe that, while part of the heat from the Gulf Stream helps to
heat North America, most of it gets blown off towards Europe.
This may be one reason why Rome, for example, is so much
warmer in winter than Boston, which lies at the same latitude as
the Eternal City. While global warming might be heating up the
Earth as a whole by small fractions of a degree Fahrenheit each
year, the effect in the North Atlantic region could be much
greater in the opposite direction. How about a 10 degree drop
just ten years from today? Ruth Curry of Woods Hole suggests
that if this happens, it could take hundreds of years to return back
to today''s "normal" climate. Global warming will have caused a
new ice age.
There''s always someone to pooh-pooh any theory. In the opinion
of Richard Seager of Columbia University''s Lamont-Doherty
Earth Observatory, the Gulf Stream plays a minor role in heating
up Europe in the winter. He feels that Europe would be warmer
than we are "even if the Atlantic were just a big stagnant ocean".
His view of the future is that European winters will become
warmer and warmer as global warming continues.
So, the battle lines are drawn. At age 74, I doubt that I shall see
which of these views is correct. However, you Boomers and
your offspring may want to hedge your bets. Take advantage of
the hot weather and summer sales to purchase that mink coat and
other winter garb to store away for 2012, just in case!
Allen F. Bortrum
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