Re: (Fwd) [asa] Cows, diet, and warming

At 05:11 PM 1/9/2007, Lawrence Johnston wrote:

"..I have also read that termites similarly
produce methane, probably by synrgistic cellulose
digesting bacteria. Does anyone have an estimate
of how much of the greenhouse gases come from this source?

@ Termites emit 20 million tons of methane per
year. (See Nature, Vol 439, pg. 148).

I don't know what percentage that makes of the
greenhouse gases. Some of the info goes hand in hand. ~ Janice

The Earth's crust contains huge amounts of
methane. Large amounts of methane are emitted to
the atmosphere through mud volcanoes which are
connected with deep geological faults or as the
main constituent of biogas formed naturally by anaerobic digestion.

Mud Volcanos http://www.answers.com/topic/mud-volcano
Biogas http://www.answers.com/topic/biogas
Anaerobic digestion http://www.answers.com/topic/anaerobic-digestion

"..Methane is created near the surface, and it is
carried into the stratosphere by rising air in
the tropics. Uncontrolled build-up of methane in
Earth's atmosphere is naturally checked...by
methane's reaction with a molecule known as the
hydroxyl radical, a hydrogen-oxygen molecule
formed when single oxygen atoms react with water vapor.

Early in the Earth's history­about 3.5 billion
years ago­there was 1,000 times as much methane
in the atmosphere as there is now. The earliest
methane was released into the atmosphere by
volcanic activity. During this time, Earth's
earliest life appeared. These first, ancient
bacteria added to the methane concentration by
converting hydrogen and carbon dioxide into
methane and water. Oxygen did not become a major
part of the atmosphere until photosynthetic
organisms evolved later in Earth's history. With
no oxygen, methane stayed in the atmosphere
longer and at higher concentrations than it does today.
http://www.answers.com/topic/methane

"...Until now, the mainstream belief
------------is that atmospheric methane chiefly
comes from bugs: from bacteria working in wet,
oxygen-less conditions, such as swamps and rice paddies.

But in a study published in the journal Nature, a
team led by Frank Keppler of the Max Planck
Institute in Germany has found living plants,
dried leaves and grass emit methane in the presence of air.

Nor is this gas just a piffling amount.

The researchers roughly estimate the world's
living vegetation emits between 62 and 236
million tonnes of methane per year, and plant
litter adds one to seven million tonnes.

This would be equivalent to between 10 and 30 per
cent of all annual global emissions of methane.

Between 1990 and 2000, satellite monitors had
detected a slowing of methane flows to the
atmosphere by around 20 million tonnes a year.

The cause for this may have been the dramatic
rate of deforestation during the same period, Dr Lowe suggested.

 From 1990-2000, more than 12 per cent of the
world's tropical forests were hacked down.

Added to this is the anecdotal data from
satellite sensors, which have occasionally
spotted inexplicably large plumes of methane over
old tropical forests, he said. ..." ~ Thursday,
January 12, 2006. Scientists question trees' role
in global warming http://www.abc.net.au/news/newsitems/200601/s1545977.htm

"...Central to the Kyoto accounting systems is
the idea that forests are a net sink for
greenhouse gases because trees store carbon
dioxide, while factories and cars, for example,
are a source of greenhouse gases because they
generate carbon dioxide. But the new research
shows that while trees store carbon dioxide, they
emit methane and methane is about 20 times more
potent as a greenhouse gas than carbon
dioxide. So forests may in fact be a source of
greenhouse gases. .......It might also be a good
time to ask our scientists and science managers:
“How could such a potentially large source of
greenhouse gases have been
overlooked?” ~ January 26, 2006 - Save the
Planet, Cut Down a Tree http://www.jennifermarohasy.com/articles81.html

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Received on Wed Jan 10 00:11:45 2007