GLOBAL WARMING AGAIN

truffler1635 at my-deja.com truffler1635 at my-deja.com
Fri Sep 17 10:26:39 EST 1999


In article <MPG.124b551966516ec898a2f7 at news.teleport.com>,
  larryc at teleport.com (Larry Caldwell) wrote:
> In article <7rq5fa$qgc$1 at nnrp1.deja.com>, truffler1635 at my-deja.com
> writes:
>
> > One way to reduce global impact of increased CO2 is to plant more trees,
> > especially fast-growing trees. A key to growing such trees is to
> > inoculate mycorrhizal fungi with them.
>
> This is a common misconception.  In fact, forests have nearly no effect
> on the buildup of atmospheric CO2.  A quick trip to the almanac will show
> why:
>
> In 1990, the world consumed the equivalent of 22,906,400,000,000
> kilograms of coal.  If previous trends hold true, current fossil fuels
> burned is approximately 26,907,980,000,000 kilograms of coal a year.
> Since a cubic meter of wood is very nearly 1000 kilograms, but wood only
> holds about 20% of the carbon of coal per kilogram, you can easily see
> that we would have to produce 134,539,900,000 cubic meters (about
> 8,000,000,000,000,000 board feet, yeah that's eight quadrillion board
> feet) of wood products a year and preserve it so it didn't burn or decay,
> which would return the carbon to the biosphere.
>
> Now, an acre of rapidly growing second growth forest can perhaps produce
> 1000 board feet a year, which means all you need is 8 trillion acres of
> second growth to ameliorate fossil fuel consumption.  That is 12 billion
> square miles (34 x 10^9 square kilometers for people who use sensible
> units).  If you covered Europe and Asia with nothing but rapidly growing
> second growth forest, you might just manage it.  Of course, if you take
> awkward things like mountains, deserts and the arctic circle into
> account, you would need to convert every productive bit of land in
> Europe, Asia, North America and South America into nothing but rapidly
> growing second growth forests.  As soon as the entire human race starves
> to death, you can let things go back to nature.
>
A fairly concice assessment Larry. But it lacks one thing: where did the
coal come from originally. Most appears geologically to have been laid
down during the Permian age. And among the most common fossils from coal
are trees.

Your growth rates for forests do not always apply, either. Mycorrhizal
fungi in quantity negate the need for fertilizers, which become a major
impact on ocean flora, which in turn dramatically impact algae, which
_do_ impact the amount of atmospheric CO2 and O2.

But I would disagree on the concept that trees do not remove CO2.
Because they are long-term perennial organisms, they effectively wall
away CO2 (at least in temperate arboreal forests) for up to 1,000 years
or more. On-going research suggests that old-growth forests remove and
keep removed large amounts of CO2 out of the atmosphere for 500 years
while growing and 500 additional years while decaying afterwards. (Of
course, some trees like cypress and cedar may be longer.)

Your accounting also does not take into consideration the amount of
forest degradation over the last 4000 years. Where are the forests of
Lebanon? Rome declined, in large part, because the pine forests it
depended upon for fuel and wood were decimated and (mostly) did not grow
back.

BTW, the only reason I can think of that coal and oil deposits were even
laid down, was a dramatic increase in atmospheric CO2 levels for quite a
long time. Whether this was from crustal or cometary CO2 is unknown. But
for several million years CO2 levels must have been so high that forest
fires could not exist. Indeed, unless volcanic activity exposed
flammable material, fire did not exist for long. Increased forest growth
is a direct result of increased atmospheric CO2 levels, according to
research at Oregon State University and elsewhere. This increased growth
is somewhere around 2-4 times the average growth rate otherwise.

I _didn't_ say forestry was an immediate solution to increased CO2
levels. But historically, it does appear to be nature's solution.

Daniel B. Wheeler



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