Agriculture Reference
In-Depth Information
is equivalent to the greenhouse emissions of the whole planet.' I struggled long and hard
with this statistic. First I had to work out that when she says 'one per cent increase in soil
carbon' (which suggests that to achieve the desired increase, the 15 million hectares would
have to start out a metre deep in solid soot) what she means is 'the conversion of one per
cent of the soil to carbon.' Next was the matter of the world's greenhouse emissions. The
annual global anthropogenic emissions of carbon are about 8Gt - but that is the equivalent
of 30 Gt of carbon dioxide, while Jones' 8Gt of carbon dioxide are around 2.16 Gt of car-
bon. Eleven tonnes of CO
2
are equivalent to about three tonnes of carbon. Perhaps she got
muddled up, its a very easy mistake, but not one you'd expect from a PhD in Soil Science.
But even if we take the lower figure, her one per cent increase consists of an annual incre-
ment of 144 tonnes of carbon per hectare - exactly ten times as much as the highest poten-
tial increase recorded by the IPCC in its overview of carbon sequestration studies, and well
over 100 times as much as the vast majority of the increases it records.
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Perplexed, not only by this, but by some other statistical inconsistencies on her website,
I emailed Christine Jones asking for clarification. She wrote back: 'We are in the middle
of an extremely busy fieldwork period here. On top of that, hundreds of e-mails come in
from all over the world every day. I suggest you READ the articles on the Amazing Carbon
website - you will find all your answers there.' I had read nearly half the website before
e-mailing, and so set down to read the rest.
After this inauspicious beginning, and given the aura of flakiness and quackery sur-
rounding a wing of the carbon farming movement, I was not overoptimistic. However
after rooting through a lot of very repetitive papers from her website and other sources, I
managed to obtain a fairly good picture of how the Australian Soil Carbon Accreditation
Scheme (ASCAS) proposes to save the planet.
Since the European settlement of Australia, 50 to 80 per cent of carbon has been lost
from most farmed soils through unsustainable farming practices reliant on heavy duty till-
age and blanket use of chemical fertilizers. This can be put back, Jones argues, by using
regenerative farming methods that use minimal tillage, keep a ground cover at all times and
have a high proportion of perennials. The method she particularly champions - in fact in
most documents it is the only one she cites - is the 'pasture cropping' or 'perennial cover
cropping' system developed by a farmer called Colin Seis. This version of zero tillage in-
volves drilling grain crops into perennial pasture at a time of year when it is dormant. It is
reliant on fertilizer; and yields of grain crops are respectable for Australia, although well
certainly hard to imagine it working in the south west of the UK, where pasture is never
dormant, except when it is frozen. There have been a number of experiments in the UK in-
volving wheat or other cereals sown into clover, which almost certainly increase soil carbon
content. Unfortunately most of the trials are more concerned with yields, which are respect-
