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

Thanks, Pim, for posting these links. I've found one myself that perhaps you'd
like to comment on:
http://www.geocraft.com/WVFossils/greenhouse_data.html

--- PvM <pvm.pandas@gmail.com> wrote:

> Of course, it's not what the earth already emits naturally, it's the
> effect of what humans have added that should be our concern. However
> there is some data about termites:
>
> <quote>
> However, data indicate that while there are large variations in the
> amount of CH4 produced by different species, the total methane source
> due to termites is probably less than 15 Tg per year, thus making a
> contribution of less than 5% to global CH4 emissions.
> </quote>
>
> The IPCC reports http://www.epa.gov/methane/sources.html
>
> Wetlands. Natural wetlands are responsible for approximately 76% of
> global methane emissions from natural sources, accounting for about
> 145 Tg of methane per year. Wetlands provide a habitat conducive to
> methane-producing (methanogenic) bacteria that produce methane during
> the decomposition of organic material. These bacteria require
> environments with no oxygen and abundant organic matter, both of which
> are present in wetland conditions.
>
> Termites. Global emissions of termites are estimated to be about 20 Tg
> per year, and account for approximately 11% of the global methane
> emissions from natural sources. Methane is produced in termites as
> part of their normal digestive process, and the amount generated
> varies among different species. Ultimately, emissions from termites
> depend largely on the population of these insects, which can also vary
> significantly among different regions of the world.
>
> Oceans. Oceans are estimated to be responsible for about 8% of the
> global methane emissions from natural sources, accounting for
> approximately 15 Tg of methane. The source of methane from oceans is
> not entirely clear, but two identified sources include the anaerobic
> digestion in marine zooplankton and fish, and also from methanogenisis
> in sediments and drainage areas along coastal regions.
>
> Hydrates. Global emissions from methane hydrates is estimated to be
> around 10 Tg of methane per year, accounting for approximately 5% of
> the global methane emissions from natural sources. Methane hydrates
> are solid deposits composed of cages of water molecules that contain
> molecules of methane. The solids can be found deep underground in
> polar regions and in ocean sediments of the outer continental margin
> throughout the world. Methane can be released from the hydrates with
> changes in temperature, pressure, salt concentrations, and other
> factors. Overall, the amount of methane stored in these hydrates
> globally is estimated to be very large with the potential for large
> releases of methane if there are significant breakdowns in the
> stability of the deposits. Because of this large potential for
> emissions, there is much ongoing scientific research related to
> analyzing and predicting how changes in the ocean environment affect
> the stability of hydrates.
>
>
> And http://www.agu.org/sci_soc/prrl/prrl0231.html
>
> In a baseline study in 1995, 60 percent of methane emissions to the
> atmosphere were the result of human activity. The IPCC's A1 scenario,
> which Fiore characterizes as "less optimistic in terms of anticipated
> emissions than a companion B1 scenario," posits economic development
> as the primary policy influencing future trends of manmade emissions
> in most countries. Under A1, emissions would increase globally from
> 1995 to 2030, but their distribution would shift. Manmade nitrogen
> oxides would decline by 10 percent in the developed world, but
> increase by 130 percent in developing countries. During the same
> period, methane emissions would increase by 43 percent globally,
> according to the A1 scenario.
>
>
> and http://www.climatescience.gov/infosheets/highlight1/default.htm
>
> Human-influenced sources of methane include landfills, natural gas and
> petroleum production and distribution systems, agricultural
> activities, coal mining, stationary and mobile combustion, wastewater
> treatment, and certain industrial processes. About 60% of global
> methane emissions come from these sources and the rest are from
> natural sources (IPCC, 2001). Natural sources include wetlands,
> termites, oceans, and hydrates (which consist of methane molecules
> each surrounded by a cage of water molecules and are present in
> seafloor deposits around the world).
>
>
> As far as trees are concerned, this is based on a recent study and is
> yet to be confirmed, nevertheless
>
> <quote>Consensus
>
> The study does not seek to explain exactly how the methane is emitted,
> nor suggest which plant species may emit more than others.
>
> Nor does it challenge scientific opinion on global warming, which has
> become rock-hard over the past five years and is now questioned only
> by a small minority.
>
> The consensus is that global warming is a fact and may already be
> affecting Earth's climate, and the big culprit is the billions of
> tonnes of CO2 spewed out by burning oil, gas and coal.
>
> The paper's earliest impact could be political, for it attacks one of
> Kyoto's conceptual cores.
>
> Under the protocol's notoriously complex rule book, industrialised
> signatories that plant forests can offset the supposed benefit against
> their national quotas of CO2. </quote>
>
> So these findings may be used politically to counter the Kyoto
> protocol as trees were seen as a way to offset CO2 sources.
>
> Keppler, the originator of the study warns
>
> <quote>Keppler cautions against 'over interpreting' his results. He
> warns that it is not only net emissions from trees that need to be
> re-evaluated. Rising temperatures caused by greenhouse gases, and
> changing atmospheric conditions caused by changing carbon dioxide
> concentrations will lead to increased methane emissions from plants
> and emphasise global warming, he told Chemistry World. 'This effect
> could be much more pronounced than the benefit you get from other
> [reforestation] programmes,' he said. </quote>
>
>
> See also
>
http://www.mpg.de/english/illustrationsDocumentation/documentation/pressReleases/2006/pressRelease200601131/index.html
>
> Global Warming - The Blame Is not with the Plants
>
> International scientific team reacts to misinterpretation of their
> research results and provides the correct perspective
>
> On 1/9/07, Janice Matchett <janmatch@earthlink.net> wrote:
> >
> > 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).
>
> To unsubscribe, send a message to majordomo@calvin.edu with
> "unsubscribe asa" (no quotes) as the body of the message.
>

Bill Hamilton
William E. Hamilton, Jr., Ph.D.
248.652.4148 (home) 248.821.8156 (mobile)
"...If God is for us, who is against us?" Rom 8:31

__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com

To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Wed Jan 10 08:24:23 2007