"Dylan Smith" wrote in message
...
On 2006-06-29, Matt Barrow wrote:
Which is a good thing. CO2 makes plants and trees grow.

And cars and power plants are way down on the list compared to natural
sources.

Human CO2 is something like only 3% of global CO2 emissions.

It's not absolute quantities in this context that are important - it's
the relative addition of man made CO2. If (as an example) the Earth's
system could keep a steady concentration of CO2 for a natural output of,
say, 100 units - and man made sources then started adding just 1 unit,
instead of a steady concentration (all things being equal) you start to
get an increase of 1 unit per unit of time.

The evidence is conclusive that recent rises in CO2 concentrations (from
280ppm in 1900 to 320ppm now) are entirely caused by human activity. We
can see that CO2 levels have only varied between 270 and 290ppm for a
good 10,000 years prior to this point. Carbon dating the CO2 in the
atmosphere shows that the recent additions of CO2 (i.e. the change from
~280ppm to 320ppm) are from the burning of fossil fuels.

It may all be well if we increased the carbon dioxide sinks by 3% also,
but generally the kind of activity that leads to the burning of fossil
fuels also leads to a reduction in the CO2 sinks.

Regarding the environmentalists' concern over CO2, here are some facts
nobody argues with:





1. Atmospheric pressure is about 15 psi (pounds/in./in.).



2. Earth's radius is about 4,000 miles.



3. CO2 constituted about 0.04 per cent of the atmosphere in 1950--.



4. CO2 now constitutes more like 0.06 per cent of the atmosphere.



From #2 we calculate that the Earth's surface area is 0.8 billion billion

square inches. And from #1 that the atmosphere weighs 11.9 billion billion
pounds. This is 6 million billion tons. Now take fact #3; 0.04 per cent is
2,400 billion tons of CO2. Half (the change since 1950) is 1,200 billion
tons. Let's call this fact #5:



5. There were 2,400 billion tons of CO2 in the atmosphere in 1950; 3,600
billion tons now, give or take a psi or two--.



6. Human activity currently releases 6 billion tons of CO2 per year.



7. Non-human activity (oceans, trees, Pinatubo, Mauna Loa, etc.) releases
200 billion tons of CO2 per year--.



Now compare fact #5 with fact #6. Simple division tells you that if every
molecule of human-released CO2 at the current rate of production stayed in
the atmosphere, it would take another 200 years for the post-1950 change to
be matched. Or looking at it backward, since minus 200 years takes us back
to before the Industrial Revolution, it means that if every CO2 molecule
from every factory, car, steam engine, barbecue, campfire, and weenie roast
that ever was since the first liberal climbed down out of a tree right up
until today was still in the atmosphere. It still wouldn't account for the
change in CO2 since 1950.



Fact #7 has been going on for a long time, a lot longer than any piddling
200 years. Comparing #5 and #7 means it takes about 12 yearsfor the average
CO2 molecule to be recycled back out of the atmosphere.



Given the above, here are some conclusions that nobody can argue with and
still claim to be a reasoning creatu



8. Human activity, carried out at the present rate indefinately (more than
12 years) cannot possibly account for more than 6 per cent of the observed
change in CO2 levels.



9. Entirely shutting off civilizationor even killing everybodycould only
have a tiny effect on global warming, if there is any such thing--.



That leaves two questions that no one knows how to answer:



Q-1. Why do all these supposedly educated, supposedly sane people want to
end civilization?



Q-2. Since humanity can't possibly be causing the CO2 level to go up, isn't
it time to start wondering about what is?



L. Van Zandt, Professor of Physics,

Purdue University, West Lafayette, Indiana