"Robert J. Bradbury" wrote:
>
> On Sat, 30 Jun 2001, Mike Lorrey wrote:
>
> > I can say that one of the best means of doing so, if you actually think
> > that CO2 is actually a threat to the climate (where the opinion among
> > scientists working in the area have apparently voted 10 to 1 against,
> > according to the petition signatures), [snip]
>
> Mike, "scientists voting" doesn't mean anything if they aren't
> reasonably informed about the topic. Arguing that we should accept
> what "scientists say" is about the same as the public "voting" about
> GMO based on the latest news report. I'm reasonably well informed
> about a lot of things but got my eyebrows raised when I actually
> investigated this problem in detail.
>
> So I'm not going to let you get away with the statement.
I have not investigated what sort of scientists are on the 1800 person
petition that claims global warming is a problem, or the 17,000 person
petition that claims it is not, this is true. The four scientists on
Stossel's program the other night are on the 17k petition and are, in
fact, involved in the research, and they have nothing but ridicule for
the idea that anthropomorphic CO2 is a significant threat.
>
> As I discuss in my paper, the current atmosphereic CO2 levels
> are 368 ppmv. The highest preveiously documented levels were
> 275 ppmv reached during the inter-glacial eras as documented
> by the Vostok ice cores. We are *way* over the CO2 level
> seen by the Earth in recent history. The fact that it is
> continually increasing demonstrates clearly that existing
> systems to absorb it cannot keep up with human activities.
Yet despite having a much higher CO2 level, we are not much warmer than
the past thousand years, while most of the last 10,000 years has
actually been far warmer than the current day. In 5,000 BC temps were
5-10 degrees warmer than the current day, with CO2 levels nearly half
the current level, with no collapse of ice caps, no worldwide floods,
yadda yadda yadda. CO2's behavior as a greenhouse gas is not linear, it
follows a curve of diminishing returns, and we've been on the plateau
for quite a while, according to my cousin Andrew, who is an ice age
geology doctoral candidate (he just finished his masters). Adding more
to the stew contributes less and less to warming at our planet's
atmospheric pressure. It is physically impossible for us to wind up in a
Venus-like runaway greenhouse situation simply because Venus never
sequestered its proto-atmosphere in limestone like Earth did (Venus has
the equivalent of ~92 earth atmospheres, and since life never evolved
there to any degree that we know of, it never sequestered most of it.
Earth started off with about 53 atmospheres worth of gas, 52 of which it
sequestered mostly in limestone, mostly prior to and during the Cambrian
period, while the remainder coalesced as our oceans, and we are left
with the surplus of nitrogen and oxygen, with trace amounts of CO2, CO,
and other compounds.)
>
> Now, the only reason we haven't seen massive global warming
> (IMO) is because the planet has a huge amount of thermal
> inertia (mostly in the oceans I'd guess) and so global
> warming accelerates very slowly.
Not really. Since the polar oceans are supposed to be warming faster
than the equator, this means that thermal conductance is moving along
pretty rapidly. While the US is 0.5 degrees warmer, Siberia is 2 degrees
warmer, and the equator is barely warmer at all. If the 'thermal
inertia' is as you say, especially with the oceans, this should not be
happening. Instead the equator should be warming faster than the poles.
The long term trend for the earth is not a greenhouse, it is toward an
ice house. CO2 freed by burning of fossil fuels will, within the next
century, be locked up mostly in carbonate coral formations that will
eventually become limestone. After that, we will burn up the methane
hydrates frozen in the ocean floors, and the CO2 from that will also
then become locked up mostly in coral, till eventually the new ice age
begins from lack of CO2, sea levels will fall dramatically as the ice
grows. The lowering of sea levels will cause a drop in pressure at the
sea floors which will cause catastrophic releases of methane hydrates
into the atmosphere, causing a new warming period, until they are locked
up more permanently in coral. This process will cycle again and again
until the earth freezes over permanently, with all carbon locked up
permenently in limestone, long before the sun warms enough from its main
sequence evolution. Venus is not the future of Earth, Mars is.
This archive was generated by hypermail 2b30 : Fri Oct 12 2001 - 14:39:41 MDT