Re: FW: - Climate Change Hearings and the roll(?) of nuclear power

[Kai Kaletsch <info@eic.nu>]

----- Original Message -----

From: "Franz Schoenhofer" <franz.schoenhofer@chello.at>

> Cutting down

> forests like in South America and other areas of the world additionally

> reduces the absorption of CO2 by photosynthesis.



The natural South American rainforest (without logging) has no mechanism for

a carbon sink. Whatever CO2 is fixed by photosynthesis is either released by

creatures living in the forest when they eat the vegetation or by fires.



If you consider a managed forest with logging, you simply move the CO2

source away from the CO2 sink in space and time, similar to what happens in

a wheat field. If the USA is a carbon sink, wheat fields could be an

explanation for that, since the USA is a net grain exporter. I don't think

the US is a net lumber exporter, so I don't think managed forestry can be

used as an explanation.



Neither a natural forest, managed forestry or agriculture lock carbon away

for any length of time and can therefore be used to balance the burning of

fossil fuels. Deforestation is a bad thing for a variety of reasons (and

results in a one time emission of CO2), but continual fixing of CO2 and

combating the greenhouse effect by the forest is not a valid argument.



(While forests do not combat the greenhouse effect by fixing carbon, a

deforested area can add to the greenhouse problem by producing methane.)



The  two mechanisms that I am aware of where carbon is fixed for a long time

are:



1. Sediments of seashells and corals become limestone. This happens in the

ocean. (If A-bomb testing kills the coral, the process stops. [Now this post

is relevant to the list again.])



2. Lakes become peat bogs. This happens in Canada and in other northern

places.



>Further I do not understand why wheat fields have enhanced radon emissions.

>The cause for enhanced emission of radon from soil would be tilling - but

>this is done in all kind of cultivations. Could you please explain?



You are correct. Radon is released during the tilling process and radon

exhalation is enhanced afterward, because the soil is loose. Cereal crops

like wheat require more tilling than some other crops like hay or fruit

orchards. They are also grown in looser, dryer soil than most root crops.

Saturated soil or water cover reduces radon emissions, so people worried

about radiation should move downwind of cranberry or rice fields.



Regards,

Kai



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