[meteorite-list] New Theory: Global Warming Caused by Tunguska Event

From: Rob McCafferty <rob_mccafferty_at_meteoritecentral.com>
Date: Wed Mar 15 18:10:10 2006
Message-ID: <20060314171340.18503.qmail_at_web50906.mail.yahoo.com>

Oh please. April the first isn't for another two
weeks.

The carbon 14 record for the last 2000 years discounts
this as a theory. The quantity of Carbon 14 in tree
rings is a good indicator of solar activity as it
reduces C14 production in the atmosphere by cosmic
rays and a good correlation exists between solar
activity and average earth temperature. So to find the
average earth temperature, count the C14 in tree rings
taking decay into account of course. The C14 count has
risen in the last 150 years and has been doing so
since the Maunder Minimum. This alone would account
for a lot of it.

Here is another example of a "meteorite detonating
with xN the hiroshima bomb". Even at x1000, would it
really contain enough water to have the effect stated?
I think not. Besisdes, I was under the impression high
altitude water got dissociated by UV radiation. (the
process causing venus to lose all its water as it got
driven higher into the altitude by a runaway
greenhouse).
I don't care how big Tunguska was, I cannot believe
that a single isolated event 100 years on is
potentially more damaging than 5billion net tonnes of
CO2 being dumped into the atmosphere every year over
the same period.

Nice story though.

Rob Mc

--- Ron Baalke <baalke_at_zagami.jpl.nasa.gov> wrote:

>
> http://www.physorg.com/news11671.html
>
> Greenhouse theory smashed by biggest stone
> Space and Earth Science
> March 13, 2006
>
> A new theory to explain global warming was revealed
> at a meeting at the
> University of Leicester (UK) and is being considered
> for publication in
> the journal "Science First Hand". The controversial
> theory has nothing
> to do with burning fossil fuels and atmospheric
> carbon dioxide levels.
> According to Vladimir Shaidurov of the Russian
> Academy of Sciences, the
> apparent rise in average global temperature recorded
> by scientists over
> the last hundred years or so could be due to
> atmospheric changes that
> are not connected to human emissions of carbon
> dioxide from the burning
> of natural gas and oil.
>
> Shaidurov explained how changes in the amount of ice
> crystals at high
> altitude could damage the layer of thin, high
> altitude clouds found in
> the mesosphere that reduce the amount of warming
> solar radiation
> reaching the earth's surface.
>
> Shaidurov has used a detailed analysis of the mean
> temperature change by
> year for the last 140 years and explains that there
> was a slight
> decrease in temperature until the early twentieth
> century. This flies in
> the face of current global warming theories that
> blame a rise in
> temperature on rising carbon dioxide emissions since
> the start of the
> industrial revolution. Shaidurov, however, suggests
> that the rise, which
> began between 1906 and 1909, could have had a very
> different cause,
> which he believes was the massive Tunguska Event,
> which rocked a remote
> part of Siberia, northwest of Lake Baikal on the
> 30th June 1908.
>
> The Tunguska Event, sometimes known as the Tungus
> Meteorite is thought
> to have resulted from an asteroid or comet entering
> the earth's
> atmosphere and exploding. The event released as much
> energy as fifteen
> one-megaton atomic bombs. As well as blasting an
> enormous amount of dust
> into the atmosphere, felling 60 million trees over
> an area of more than
> 2000 square kilometres. Shaidurov suggests that this
> explosion would
> have caused "considerable stirring of the high
> layers of atmosphere and
> change its structure." Such meteoric disruption was
> the trigger for the
> subsequent rise in global temperatures.
>
> Global warming is thought to be caused by the
> "greenhouse effect".
> Energy from the sun reaches the earth's surface and
> warms it, without
> the greenhouse effect most of this energy is then
> lost as the heat
> radiates back into space. However, the presence of
> so-called greenhouse
> gases at high altitude absorb much of this energy
> and then radiate a
> proportion back towards the earth's surface. Causing
> temperatures to rise.
>
> Many natural gases and some of those released by
> conventional power
> stations, vehicle and aircraft exhausts act as
> greenhouse gases. Carbon
> dioxide, natural gas, or methane, and
> chlorofluorocarbons (CFCs) are all
> potent greenhouse gases. Carbon dioxide and methane
> are found naturally
> in the atmosphere, but it is the gradual rise in
> levels of these gases
> since the industrial revolution, and in particular
> the beginning of the
> twentieth century, that scientists have blamed for
> the gradual rise in
> recorded global temperature. Attempts to reverse
> global warming, such as
> the Kyoto Protocol, have centred on controlling and
> even reducing CO2
> emissions.
>
> However, the most potent greenhouse gas is water,
> explains Shaidurov and
> it is this compound on which his study focuses.
> According to Shaidurov,
> only small changes in the atmospheric levels of
> water, in the form of
> vapour and ice crystals can contribute to
> significant changes to the
> temperature of the earth's surface, which far
> outweighs the effects of
> carbon dioxide and other gases released by human
> activities. Just a rise
> of 1% of water vapour could raise the global average
> temperature of
> Earth's surface more then 4 degrees Celsius.
>
> The role of water vapour in controlling our planet's
> temperature was
> hinted at almost 150 years ago by Irish scientist
> John Tyndall. Tyndall,
> who also provided an explanation as to why the sky
> is blue, explained
> the problem: "The strongest radiant heat absorber,
> is the most important
> gas controlling Earth's temperature. Without water
> vapour, he wrote, the
> Earth's surface would be 'held fast in the iron grip
> of frost'." Thin
> clouds at high altitude allow sunlight to reach the
> earth's surface, but
> reflect back radiated heat, acting as an insulating
> greenhouse layer.
>
> Water vapour levels are even less within our control
> than CO2 levels.
> According to Andrew E. Dessler of the Texas A & M
> University writing in
> 'The Science and Politics of Global Climate Change',
> "Human activities
> do not control all greenhouse gases, however. The
> most powerful
> greenhouse gas in the atmosphere is water vapour, he
> says, "Human
> activities have little direct control over its
> atmospheric abundance,
> which is controlled instead by the worldwide balance
> between evaporation
> from the oceans and precipitation."
>
> As such, Shaidurov has concluded that only an
> enormous natural
> phenomenon, such as an asteroid or comet impact or
> airburst, could
> seriously disturb atmospheric water levels,
> destroying persistent
> so-called 'silver', or noctilucent, clouds composed
> of ice crystals in
> the high altitude mesosphere (50 to 85km). The
> Tunguska Event was just
> such an event, and coincides with the period of time
> during which global
> temperatures appear to have been rising the most
> steadily - the
> twentieth century. There are many hypothetical
> mechanisms of how this
> mesosphere catastrophe might have occurred, and
> future research is
> needed to provide a definitive answer.
>
> Source: University of Leicester
> ______________________________________________
> Meteorite-list mailing list
> Meteorite-list_at_meteoritecentral.com
>
http://six.pairlist.net/mailman/listinfo/meteorite-list
>


__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
Received on Tue 14 Mar 2006 12:13:40 PM PST