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[Gerald Brittell <gabrittell AT gmail.com>]

Forgive me please for diverting from the purpose of the discussion.  But
> does a modern car put out enough pollutants to kill a person.  Never
> researched the subject but I've heard that from at least one mechanic.
>  Which doesn't detract from the point being made.
>

Van Dell, You raise some interesting points.  I think your mechanic may be
right about 2009 cars.  I googled a pdf file that stated later model cars
with catalytic converters indeed have reduced CO to below 1% of former
levels and therefore are no longer a  kind way to euthanise unwanted trapped
myna birds!  I don't know about 2009 auto's but they may well have
eliminated the most of co, certainly not co2.  Of course the greatest
emitter of co2 is not transportation and I guess my point was that even the
atmosphere of the earth is a finite, closed garage, given enough cars and
trucks, factories, power plants, plows, and people ... as I know you know.


> Back to the subject at hand.  Even if global warming hasn't happened yet,
> is it possible?


Some of the pertinent (and fascinating) reading I have done makes it clear
that  it has happened many times in the past.  The greatest of all
'extinction events', the PT event, which eliminated 95% of all species then
extant, is said to have most likely been caused by rising co2 levels from a
huge volcano lava flow over coal deposits in Russia 25 million years ago.
Some experts suggest that similar amounts of hydrocarbons may have been
burned by man in the past hundred years as was then burned over several
thousands of years.  'Course there are also those who say the earth was
created only 6000 years ago. and one has to think for oneself.

I've yet to hear any believable argument that it can't.  It seems to boil
> down to: "the climate varies naturally, so therefore any warming we see is
> due to natural conditions".  How does the first fact prove the second??
>

Great observation.  It doesn't.

A most important dynamic not appreciated by most of us laymen is the extent
temperature on the surface of the earth is determined almost entirely by the
greenhouse gas levels in the atmosphere. The distance from the sun, the
changing angles of incidence of it's radiation on the earth, and solar
activity such as sun spots, all have some influence but are almost
insignificant compared to how co2 moderates and regulates the temperature.
Without it, we would have Martian like cold when the sun does not shine, and
toast to a crisp when it did,  With much more, we'd bake as we would on
Venus. It is this well known and quantified facts that convinces almost all
experts that indeed what man has done is the cause of present climate
changes, knowing accurately how much hydrocarbons have been burned and how
many parts per million co2 has increased in the last century.

>
> The earth is not getting bigger but the population is increasing, and
> amount of pollutants emitted per person is going up.  Surely at some point
> we will pollute more than nature can absorb.
> One thing might well keep that disaster from happening.  That is if we run
> out of fossil fuels before that time.
>

I think as do other persons who know a lot more about it than I do that
another thing that is more likely to happen before running out of fossil
fuels, even though the price might get pretty dear, is we run out of human
beings to burn it.  If all the available hydrocarbons still remaining are
used as they are now, conditions on earth again could not possibly support
higher forms of life.  It was life itself that lowered the concentrations of
co2 in the atmosphere, sequestering it in the earth, as well as freeing the
oxygen. Releasing again all that carbon, and so quickly, will make short
order of this development long before we've burned the last bit. imo

Van Dell
>