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03/10/2004
Water Here and on Mars
Last week we discussed how our oceans and some of its
creatures serve as sinks for carbon, helping to slow down global
warming. Global warming and water made the headlines last
week. Water on Mars grabbed the biggest headlines. However,
Brian Trumbore called my attention to a New York Times article
about a report prepared for the Pentagon on possible scientific
and political consequences of global warming. The report
contains a frightening scenario of the “colding” and associated
effects that the warming might engender.
What is the evidence for water on Mars? The NASA/JPL Web
site cites the finding by the Opportunity rover of the presence of
“vugs” in one of the Mars rocks. I confess my ignorance of the
term vug. Here on Earth, if there’s a rock sitting in very briny
water loaded with salts of some form, crystals of the salts will
form in the rock. Later, the salts may be eroded away, or if
exposed to less salty water, may be redissolved. In either case,
the removal of the salts leaves behind voids. These voids or
indentations are vugs. Apparently, the term vug derives from the
Cornish vooga, and is defined as a cavity, void or large pore in a
rock commonly lined with mineral precipitates. Opportunity
found indentations that were about a centimeter long and a
quarter of a centimeter or less in width. The patterns looks to the
experts to be quite similar to vugs in rocks on our own planet.
Two other features suggest the possible presence of water but
aren’t as firmly established as originating from an aqueous
source. One feature is the presence of spherical particles the size
of BBs. They could be formed by minerals forming in the small
pores of porous rock. However, there are also the possibilities
they could be formed during either volcanic eruptions or as a
result of meteor impacts. The other feature is “cross bedding”.
This is the formation of layers in the rock that run at angles to the
main layer patterns. Such cross bedding can result from either
wind or water. Both the spherical particles and the cross bedding
are likely due to water in the views of mission scientists but
further work is needed to confirm their suspicions.
To me, an unambiguous piece of evidence is the identification of
in the rock outcrop of “a hydrated iron sulfate mineral known as
jarosite.” If a mineral is hydrated, that means it contains water –
period. Three types of spectrometers were used to study the rock
outcrop. Two of them, a Mossbauer spectrometer and an alpha
particle X-ray spectrometer were supplied by Germany. A third
one is the thermal emission spectrometer. I won’t discuss the
operation of these instruments here but they permit the
identification of the chemical elements and minerals present in
the rocks. The presence of chlorine and bromine indicate that
chloride and bromide salts are also likely to be present. Here on
Earth, such mineral-rich rocks have either been formed in water
or have been altered through long exposure to water.
Is all the current and future attention to Mars worth it? Not
everyone thinks so. In an article by Joseph Verrengia in the
March 7 edition of the Naples Daily News, critics of the
proposed emphasis on Mars with an ultimate manned mission are
quoted. One of the critics is Sylvia Earle, renowned explorer of
the ocean depths. She points out that our ocean depths are vastly
less well mapped than is Mars and maintains that the future of
mankind is certainly more closely related to what happens in our
oceans than what we find on Mars. Her response to the finding
of water on Mars is essentially, “Hey, we suspected that all
along!” In fairness, most critics don’t advocate cutting NASA’s
space budget but do think more money should be devoted to our
own waters.
Peter Schwartz and Doug Randall would probably agree with
Earle’s view. They are the authors of a report commissioned by
the Pentagon’s Andrew W. Marshall, whose bailiwick is
apparently the assessment of long-term threats. I was surprised
the Pentagon was so interested in global warming but, on reading
the unclassified report, titled “An Abrupt Climate Change
Scenario and Its Implications for United States National
Security”, I can see why. The bottom line of the report is that
global warming and the resulting melting of glaciers and other
ice in the Arctic could lead to widespread conflicts, even nuclear
war. All this could happen much sooner than you think.
We have discussed previously how fresh water introduced into
the North Atlantic by Arctic melting could prompt a shutdown of
the so-called “thermohaline conveyor”. This is the global
seawater circulation pattern that covers the Atlantic, Pacific and
Indian Oceans and includes the Gulf Stream that warms part of
the U.S. A shutdown of the thermohaline conveyor has
happened before. The authors of the Pentagon report have taken
as their scenario a shutdown of the sort that happened 8,200
years ago, relatively recently on a geological time scale. They
admit that this may be a drastic scenario, more extreme than
what may actually happen. However, they point out that the
8,200-years-ago shutdown altered the climate abruptly and for a
prolonged period of a hundred years. Their argument is that we
need to plan for such an event should it actually transpire.
What are the consequences envisioned in this scenario of global
warming? Without the warming of the thermohaline conveyor,
North America and in Asia would cool down, not heat up, by as
much as 5 degrees Fahrenheit on average while the cooling
would be up to 6 degrees in northern Europe. In contrast,
Australia, South America and southern Africa would heat up by
as much as 4 degrees on average. Drought conditions would
persist for key agricultural regions in the U.S. and Europe while
strong winter storms and more windy conditions would magnify
the hardships resulting from the climatic changes.
There would be a net global reduction in food production and
shortages of fresh water. The term “carrying capacity” becomes
important. For centuries, some have warned of the time when
the world population becomes so large that the capacity of our
Earth to sustain that population is lost. The scenario envisions a
situation wherein those nations with adequate resources become
fortresses, defending those resources. Other nations, with
inadequate carrying capacity, become aggressors, fighting for
their survival. Old alliances based on common interests,
religious beliefs and the like would be replaced by new alliances
based strictly on survival.
When could all this happen? The authors of the Pentagon report
assert that today, while there is a general feeling that global
warming is real, the warming trend is deemed to be so gradual
that mankind will be able to adapt to the slowly changing climes.
The 8,200 years ago scenario, however, is not gradual. The
thermohaline conveyor could shut down much more quickly than
we think. What if it shuts down only 6 years from now? We in
the New Jersey area would start to experience cooler, drier,
windier weather and by 2020 we would join Asia and Europe in
having our 5 or 6 degree drops in average temperature.
Things go from bad to worse, with torrential rains, flooding,
droughts, high winds, etc. replacing benign weather patterns all
over the world. Widespread famine sets in as crop yields fall.
Fish migrate as the ocean temperatures change, denying
fishermen their livelihoods and their regions a source of food.
Severe droughts and water shortages in some areas will contrast
with extreme flooding in other areas. Wars break out and all
manner of dire political, military and economic consequences
result. I leave it to the interested reader to access this report and
peruse it in detail. (Brian Trumbore sent me a copy but,
according to the Times article, it’s available at
www.ems.org/climate/pentagon-climate-change.pdf)
Scientists are not ignoring the possibility of shutdown of the
thermocline conveyor. You might have seen a news report that
just last Saturday, March 6, 12 Russian researchers were rescued
from their floating ice station 400 miles from the North Pole.
According to a report by Andrew Revkin that appeared in the
March 7 Naples Daily News, the Russian researchers had been
stationed on this floating ice since last April, almost a year!
Their mission was to study long-term Arctic warming and the
melting of the Arctic ice. For the Russians, the mission
represented the resumption of a 31-year series of such year-round
missions on drifting ice on the Arctic Ocean back in the period
from 1937 to 1991.
Sustained monitoring of Arctic climactic conditions is not an
easy task and the Russians deserve a lot of credit. The rescue, by
helicopters flown well beyond their normal range, was
necessitated when three-story high ridges of sea ice crushed or
submerged most of the camp! Makes me appreciate the sunny
warmth here on Marco Island in Florida even more.
Allen F. Bortrum
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