Re: Camping Stove



A

Ambrose Nankivell

Guest
In news:[email protected],
Nick Kew <[email protected]> typed:
> In article <[email protected]>,
> "Ambrose Nankivell" <[email protected]>
> writes:
>
>>> Didn't I read that it took more energy to make biodiesel than it
>>> contained?
>>>

>> Quite possibly.
>>
>> But they were bullshitting propagandists who said so.
>>
>> The propagandists on my side say there's an 84% energy yield on it
>> from their studies. Which is not dissimilar to the 84% energy yield
>> from petrodiesel. Just that the biodiesel does it inna
>> carbon-neutral stylee,

>
> Bzzt, big red herring there.
>
> In its natural state, the land devoted to growing biodiesel will be
> covered in vegetation, and absorbing CO2. When growing for man to
> burn, the same is true. Except that burning it then re-releases the
> CO2.
> So you've just neutralised land that *should* be making a positive
> contribution - which is not so very different overall to burning
> fossils but leaving todays plants to grow instead.


I don't quite understand how land can make a positive contribution to being
a carbon sink except for turning the soil into a carbon sink, and presumably
that runs the risk of liberating quite a lot of methane from the rotting
vegetation as well, which may be a gain in terms of CO2 levels, but hardly
in terms of greenhouse gases.

Presumably soil also has an output role to play in the carbon cycle as not
all the world's carbon has dissappeared into soil and coal (although of
course a fair proportion did upon the invention of the tree, but since then,
AIUI CO2 levels haven't changed much)

> Creative accounting is all about conveniently hiding things like that.


But it's fairly safe to assume that cultivated land will also be producing
products that are turned into carbon dioxide somehow, except for trees that
eventually end up as landfill.

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