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03/30/2005
Carbon Control
I’ve just returned from my morning walk on the beach here on
Marco Island. It was a nice, somewhat brisk morning and there
was a major shell wash-up on the beach, with sea urchins by the
scores in some spots. The brisk walk not only enriched my soul
and body but, unexpectedly, my pocketbook. Among the shells,
I found a water-soaked 20-dollar bill! That more than covers the
cost of my lunch of conch chowder, two grouper balls and my
half of the slice of coconut crunch pie shared with my wife
yesterday at Little Bar restaurant.
One more day and we head back to New Jersey. It’ll be strange
be where the newspapers will not contain daily headlines related
to traffic, red tide, sewage and water drainage problems. On
Marco currently, there’s controversy over a proposal to build a
walking bridge over a lagoon from a popular beach to allow
beachgoers to save a bit of a walk to get to the Gulf. To me, the
bridge would be an environmental disaster, threatening not only
an intervening bird sanctuary but also the pristine nature of that
section of the Gulf beach, with no hotels and only dedicated
walkers or waders who now enjoying its farthest reaches.
We’ve discussed frequently an environmental threat that would
make any adverse effects of a walkway over a lagoon miniscule
by comparison. Given the harsh winter in the Northeast and the
relatively cool temperatures during much of our Florida stay, it’s
hard to believe that global warming is a problem. An article in
the March 21 issue of Chemical and Engineering News (C&EN)
by Bette Hileman provides a sobering reminder that we have a
problem and the main culprit is carbon dioxide, CO2.
Although the vast majority of the scientific community accepts
global warming as real and a threat that should be addressed
now, some still question its existence. Or, some who accept that
warming is occurring also believe that it is due to natural climate
cycles, not to human activities. One problem has been lack of a
model that explains past trends and is capable of trustworthy
prediction of future trends. Hileman says that has changed,
based on work presented at the annual meeting of the American
Association for the Advancement of Science in Washington last
month. Researchers now have a model in which the rising
surface water temperatures in the major oceans are replicated
with remarkable accuracy.
The average temperatures of the oceans’ surface waters have
been rising since 1960 and the model indicts carbon dioxide,
CO2, as the culprit that is largely responsible. While we may not
notice any unusual warming in Florida or in New Jersey, the
Arctic Ocean, for example, is undergoing an unprecedented
change, with the amount of summer sea ice declining 20 percent
in just 25 years or so. If we keep feeding CO2 into the air at the
current rate, the Arctic will probably have no sea ice by the end
of this century. Already, populations of various animals that
depend on sea ice are declining.
The model involves essentially two calculations for each of the
oceans. The results are two bands of temperatures of the ocean
water as a function of depth, one taking into account natural
climate variations over the years, the other taking into account in
addition the contributions of greenhouse gases from human
activities into our atmosphere. The results of the model
calculations are compared with actual measurements of ocean
water temperatures at various depths over the years compared
with the results of similar measurements in 1960.
The results clearly indicate that CO2 is the main cause of the
warming. As we’ve discussed before, the nightmare scenario is
warming in the Antarctic causing the collapse of the West
Antarctic Ice Sheet. If that happens, Marco and half of Florida
will be under water, along with many of the world’s major cities.
While the reported advances in modeling our atmosphere and
climate are impressive, a big challenge remains. We don’t have
a model that will tell us the “thresholds” for various doomsday
scenarios. In addition to the collapse of the ice sheet, other
calamities that can result from global warming are bleaching of
the corals over a large area, upsetting the marine life and
environment, and a shutdown of the global ocean circulation
system, a possible result of warming in the Arctic regions. We
don’t know how much CO2 in the atmosphere will trigger any or
all of these catastrophes or even if we’ve already passed the
threshold for one or more of them.
Is anything being done to slow the emission of CO2 into our
atmosphere? Brian Trumbore sent me a section of our Jersey
paper, the Star Ledger, which devoted 6 full pages (no ads) of its
March 6 Sunday edition to an impressive report by Kevin
Coughlin entitled “To Bury a Gas: A Shot in the Dark”.
Coughlin spent four months in the U.S. and Canada visiting sites
and interviewing leading scientists and policy-makers about how
they are dealing or hope to deal with the CO2 problem.
As we’ve discussed many times, it’s the dose that counts.
Without CO2, we couldn’t live – plants grow by using CO2 in
photosynthesis. We’ve also talked about CO2 in large doses
killing large numbers of people in Africa when CO2 suddenly
erupts from a lake like when you open a warm bottle of soda.
Today, our “dose” of CO2 in our atmosphere is too high and
rising. What to do? One approach is “sequestration”. You try to
sequester the CO2 by putting it underground or into the ocean.
One way to sequester CO2 is to compress it to what’s known as a
“supercritical” state, in which it behaves like a liquid. Various
energy companies are using this approach to deal with CO2
that’s formed during their production of oil or other fuels. For
example, the Petroleum Research Centre in Saskatchewan,
Canada is pumping huge quantities of liquid CO2 into deep
wells. Surprisingly, that CO2 comes from a synthetic fuels plant
200 miles away in North Dakota. A Norwegian company,
Statoil, is injecting millions of tons of liquid carbon dioxide
3,000 feet below the floor of the North Sea. The British
company BP is pumping CO2 a mile deep in the Algerian desert.
These sequestration efforts are laudable and there are some 40
such efforts worldwide, according to Coughlin. Some worry that
sequestration could in some cases be a ticking time bomb if some
natural or manmade catastrophe caused a sudden eruption of
CO2 from its storage space. It isn’t only in Africa that CO2 has
killed. Coughlin’s article cites the case of a skier in California’s
Mammoth Mountain area who was believed to have died when
CO2 vented from some sort of geologic formation.
The Ledger article shows coal being unloaded from a barge in
Jersey City, less than half an hour’s drive from my home. The
coal is destined for a power generating station, declared by an
interest group to be the largest emitter of CO2 in New Jersey.
This is your everyday standard pulverized coal power generating
plant. About 4 hours drive from here on Marco, near Tampa, is
the Polk Power Station, another kind of power plant, one of only
four in the world. In the Jersey plant, the coal is ground into a
powder and burned in a huge furnace, heating water to form
steam that drives turbines to generate electricity. The impurities
and CO2 goes out the smokestack.
The Polk plant, in the little town of Fort Lonesome, utilizes so-
called “Clean Coal” coal gas technology. Here, coal is mixed
with water to form a paste that is placed in a “gasifying tank”,
where the paste is heated in a low-oxygen, slow burning
environment and forms hydrogen and carbon monoxide. Both
the hydrogen and carbon monoxide are then burned in a gas
turbine to generate electricity and steam formed in the gasifying
tank is also used to turn a steam turbine to make more power.
The burnt carbon monoxide forms CO2, which can be captured
and sequestered. The waste ash is used in cement production and
sulfur is collected for use in fertilizer and other uses.
All this sounds great but building and running a clean coal gas
plant is expensive and there are problems with using dirty coal as
raw material. Also, my impression is that Polk is not yet
sequestering the CO2. It is still a cleaner plant, however.
Meanwhile, let’s hope we’ve not crossed a threshold. Next time,
back in CO2-laden New Jersey! NOTE: There will not be a new
column next week – Brian Trumbore has suggested that I take a
week off to take care of accumulated business and start work on
income tax matters. Sounds good to me.
Allen F. Bortrum
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