Page 4 ^ ^ The Clarion ^
Climate change more than just a myth
by Dr. Jim Reynolds
Faculty Contributor
The climate is changing; few Earth
scientists deny that. The Arctic Ocean is
melting. There is only one way to melt ice
at 1 atmosphere of pressure.
An ice free Arctic Ocean will create
drastic changes in the ocean and atmospheric
circulation patterns that govern climate.
Seven years ago I first expressed my opinion
that these changes will fairly rapidly bring
a return to Ice Age conditions.
Gas bubbles trapped in
the ice of the great ice caps
of Antarctica, Greenland,
Iceland, Patagonia, and
Baffin Island provide
continuous records of
atmospheric compositions
going back hundreds of
thousands of years and can
usually be dated to within a
few tens of years.
The annual ice layer stratigraphy is
calibrated by dated volcanic ash deposits
from gigantic eruptions and other
techniques. Carbon dioxide concentrations
remained fairly constant for hundreds of
thousands of years.
Only when burning coal began in earnest,
at the dawn of the Industrial Revolution,
did CO2 concentration begin to rise. It has
continued to rise ever since.
Accompanying the rise, exponential
growth ofthe human population translated to
higher demand for carbon-based energy.
We emit 26 billion tons of carbon
dioxide into the atmosphere each year
Carbon dioxide absorbs heat and retains it
in the atmosphere a little longer than it used
to do before radiating it back into space.
With this energy pileup taking place in
the sky, a rise in temperature is the only
recourse.
Priorto the Industrial Revolution, biomass
was used as the major energy source. It was
harvested from the environment and cycled
back into the environment at a sustainable
rate. Coal was only a minor energy source,
used locally since antiquity.
Earlier in Earth history, carbon dioxide
was more abundant in the atmosphere.
Much of the carbon removed from the early
atmosphere eventually ended up in plants
through photosynthesis.
Forests first appeared about 400 million
years ago. Coal forms from plant leaves
and twigs submerged in swamps. These
decompose but once all of the oxygen in the
water is used up the decay ceases; organic
litter accumulates, sequestering the carbon
for long periods of time. Earth experienced
two major eras of coal formation: 1) the
Pennsylvanian Period (325-286 million
years ago) and the upper Cretaceous Period
(-100-65 million years ago).
Both times coincided with very high
sea levels that flooded the
continental lowlands. Numerous
river delta swamps developed
in the shallow seas. A seaway
stretched from the Gulf of
Mexico to the Arctic Ocean in
the Cretaceous.
Climate change deniers
frequently claim that Earth’s
atmosphere is too big for us
to have any long-term effect
on it.
One of my favorite tales from Geology
is about the evolution of the modern
atmosphere. Much simpler organisms
slowly changed its chemistry over a long
period of time.
Earth became a planet about
4,500,000,000 years ago when it ceased
being a molten protoplanet and formed a
thin crust. Plate tectonics probably started
the same day.
The planet was under constant
bombardment from asteroids, meteors, and
comets. Comets are composed primarily of
ice and are credited with delivery of Earth’s
water supply from the cometary storeroom
in the outer reaches of the Solar System.
Low areas filled with water; water
vapor billowed into the air as it cooled
the hot rocks below. Gases released from
volcanoes, tectonic fissures, and areas
where impacts punctured the thin crust
added nitrogen, carbon dioxide, carbon
monoxide, ammonia, nitrogen dioxide,
sulfur dioxide, hydrogen sulfide, and
hydrochloric acid: all in all a ghastly lethal
mixture.
When it rained, the dissolved gases
created a primordial caustic acid soup for
an ocean.
Acids dissolved trilhons of tons of iron
minerals into the ocean during the first
billion years of Earth history.
The water had a distinct dark, murky
color Today’s ocean has no dissolved iron.
What happened?
Somehow life evolved in that poisonous
porridge of an ocean. Since there was no
oxygen, different primitive bacteria evolved
to extract eneigy from the chemicals present
in their environment.
Some learned to live off of sulfur
dioxide, others from hydrogen sulfide.
Cyanobacteria used sunlight to convert
carbon dioxide and water into a sugar,
producing a waste gas of oxygen (O2).
Photosynthesis was bom.
As soon as that first bubble of oxygen hit
the water, it oxidized some dissolved iron
ions to form an iron oxide mineral: hematite
(FcjOj) or magnetite (Fc304).
Neither of these minerals dissolves
readily in acid water so the mineral grains
plunked down on the ocean floor This
started a rain of oceanic iron that continued
for the next billion years.
Virtually all of the of the great iron
deposits society uses formed during this
period. In the U.S., these rocks, called
Banded Iron Formation, are found in
northern Minnesota.
The iron rain ended about two and a half
billionyearsago. Seawater finally started to
absorb the oxygen, gradually neutralizing
the acids.
Since oxygen was toxic to most life
forms, they died off, making more room
for the photosynthisizers. Oxygen-tolerant
organisms evolved and continue to dominate
the planet.
Eventually, oxygen leaked into the
atmosphere but before it could build up,
it had to oxidize all of the iron minerals
that had weathered out of the rocks on the
barren continents.
The continents rusted red before
oxygen finally began to accumulate in
the atmosphere. It’s been accumulating
ever since, now comprising 21% of the
atmosphere.
Coal and hydrocarbons are fossil
sunlight, sequestered ancient energy and
carbon from the ancient environment. On
Earth, we add 71 million tons of carbon
see Atmosphere, p. 6