People
are always talking about the weather, but I am proposing that we do something
about it. This is the first of three (or maybe more) posts about reducing
reversing global warming.
People have been
talking and writing about global warming since they stopped talking about the
next ice age; that was around 1980. SO far it has all be words. It climate
scientists are so sure that human activity has been causing a rise in
temperatures, then we should correct the damage before it will be too late.
According to the
climate scientists atmospheric CO2 is the thing that has caused rising
temperatures, so we should bring the CO2 down to pre-industrial levels, and one
method for doing that has been known since back when climate scientists were
talking about the new ice age that was about to start. There were articles
about how cooling started, and one of the theories was that seeding the oceans
with iron would cause plankton blooms that would soak up CO2, and shrimp and
other small animals would eat the plankton and multiply, thus exhaling CO2, so
there would be no net change in the amount of atmospheric CO2, except for that carbon
that would fall to the bottom of the ocean when the predators defecated. More
recently it has been theorized that iron rich dust blown from deserts blowing into
the oceans led to ice ages during the last four million years. (See link below)
People
have, as the linked article states, tested part of this by spreading iron dust
on the ocean. That has resulted in plankton blooms, as one would expect. But no
one has dumped in enough iron to change the atmosphere at all. If the theory is
correct, then a billion tons of iron dust would be enough to remove a
substantial amount of CO2 from the atmosphere.
Even
though a billion tons may seem like an amazingly large amount of iron, it isn’t
all that much. Consider that a 10x10 steel I-beam weighs about fifty pounds per
linear foot, so a billion pounds would translate to twenty million linear feet
of bean, and if we cut the beam into forty foot sections, then there only be
five hundred thousand beams, or the amount in a small city.
The
iron would have to be ground rather finely. Single celled animals would have to
eat the dust, and it would have to be light enough that it could float on a
breeze. For that reason the iron would have to be ground to that small size. It
wouldn’t make much difference whether the iron were pure or oxidized, so we
could grind up ore very finely and use that, rather than wasting refined metal.
There would be extraneous material in the ground ore, but that wouldn’t hurt,
and it might help. U.S. production of iron ore is about two billion metric tons
annually, so a twenty-five percent increase for two years would produce all of
the iron dust we would need. If that schedule became a problem, then we could
stretch production over another year or two. And, if it turned out that
applications of iron dust would have to continue, it could become a permanent
industry.
The
actual schedule would have to be determined by experiments that have not yet
been done that would show whether continued applications of iron dust were
necessary and whether the applications would be continuous or periodic. Pouring
on too much might just result in the extra sinking to the ocean bed.
Another
thing that we don’t know is whether the iron dust causing a phytoplankton bloom
causing a drop in CO2 levels would have immediate effects. As we can see from
last fifteen years increases in CO2 do not cause immediate temperature rises,
and the same may be true of decreases on CO2 levels. We also do not know
whether the increase in animals that would eat the phytoplankton would have any
effect.
It
might be wise to regard the first ten years of applying iron dust to the ocean as
an experiment to see whether it would be effective. An alternative theory about
atmospheric CO2 and climate is that the CO2 is an effect of increasing
temperatures, rather than a cause. I won’t argue this position, because we
should be planning to test the theory.
I’ll present another
method next time.
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