My motivation is multifaceted. I understand the magic of being in
a swamp at dawn with a zillion diverse life forms, I’ve watched a good
friend die slowly of bowel cancer, I’ve seen all forms of
intensive farming first hand, and I understand viscerally what a
10 year el-nino would do to Australia and what monsoon failure would
do to Asia.

You also have to account of the one-off massive rundown of soil carbon as a result of clearing and cultivation. And now still declining. And most cropping DOES use nitrogenous fertiliser.

I would expect to see nitrogen fertiliser used on intensive dairy pasture in Victoria, possibly irrigated. The economics of fertilising of extensive woodland or rangeland systems would be prohibitive. Indeed grass protein and energy can be so low that it is common for northern Australian production systems with Bos indicus hybrids to use urea/molasses licks to supplement animals.

Indeed many beef aficionados prefer the taste of Diamantina grass fed systems and eschew feed-lot “finished” beef (Wagyu connoisseurs roll eyes)

I don’t have any data on forest versus grassland sequestration. Proper forests would have to be much higher. But we’re not talking forests – woodlands have scattered tree – i.e tree and grassland mixtures. Fire regime often determines the balance. More fire – less trees and more grass. Less fire more trees and less grass.

But Geoff let me encourage you to continue. Any criticism offered in a scholarly light. Meat and Liverstock Authority are very conscious of their greenhouse emission exposure and are actively involved in seeking ways to reduce emissions. However if one’s motivation is the ethics of meat consumption that may not be seen as helpful.

If you do full carbon accounting of now compared to pre-european, then
you have to start with the negative impact of about 60-70m ha of
clearing (this is what is left of 100m when you take out
cropping/urban/forestry). Then add emissions from 28m cattle and 80m sheep.

The figure of 100m ha cleared is a net figure and is composed
of ~91m or woody native veg and ~9m other see Soe 2006.

Do you have any data showing that any grassland sequesters
more carbon (above and below) than any forest type? I haven’t seen
any data to this effect.

The point anyway is that a full wall-to-wall carbon accounting of our grazed woodlands with a comparison to pre-European condition might be surprising.

Regarding Qld and grazing. Indonesia and Qld are about the same size (19m ha)
and have about the same cattle population (11m). Only about 4m ha are
palm oil in Indo. So how much of that massive deforestation is down to cattle?
Probably rather more than is due to palm oil. The SBS doco “The Burning
Season”, characteristically forgot to mention cattle. Cattle … what
cattle … we didn’t see any cattle … oh, thats for hamburgers, that’s
different … but palm oil … I don’t eat palm oil … they burn
trees for that! The horror, the horror!

Lastly, no-one is claiming that cropping doesn’t have
serious environmental problems,
there is no free lunch, but at least it produces a substantial
quantity of safe food in return.

85% of Queensland is grazed – most of it is not arable for cropping. What is useful for agriculture has been developed.

Figure 28 doesn’t even pass the giggle test for Australia IMO.

Jared Diamond is often wrong about Australian ecological issues – Fertilisation of non-irrigated pasture is common? In the NT ?? How much again? ROTFL.

Tothill and Gillies would put only 20% of northern Australian grazing lands in Class C condition.

You also need to do the full budget on cropping soils – vast amounts of soil carbon lost and still decreasing. http://www.publish.csiro.au/paper/SR99042.htm Emissions of NOx from nitrogenous fertilisers. Additions of superphosphate. Soil acidification. Structural decline. Highly variable ENSO production environment. Massive river diversions for irrigation schemes. Methane emissions from major dams. Nutrient loss into waterways. Cropping also has more than its share of issues.

If you want to make arguments on ethical grounds of eating meat, cruelty in production systems or human health – fair enough – but the above ecological analysis in the Australian context isn’t convincing IMO. However I encourage you to try harder. Simply there are too many people on the planet to have food production systems that are not in some respects exploitative. Agriculturalists and natural resource scientists are striving hard for some sense of balance.

2) Globally, LLS has a figure for ammonia production: 23 million tonnes from
livestock and 3 million tonnes from wildlife. I think that says it all.

Do we even know whether our current savanna woodland ecosystems are net greenhouse improvements over the “original state” which would have been much more open with fewer trees.

The presumption is that European pastoralists have changed the greenhouse balance to the negative – it may not be so? (or at least that simple).

And savannas occupy a large part of the globe – and are also affected by highly variable rainfall – ENSO – and again likely to be affected by climate change.

Increasing atmospheric CO2 may also preference woody C3 plants over C4 grasses. (controversial perhaps).

(#2 Mitchel) My general rule-of-thumb is that we should seek to use the minimum
land to feed people and leave evolution to “manage” the rest. Human
management costs energy and materials and usually means robbing metaphorically
robbing peter to pay paul. There are always exceptions to rules of thumb!

When ruminants like cattle are brought into the picture, it becomes more complex, but the paradigm that for each land state there is a fixed net contribution still seems valid. A given surface area can support only so many animals, and so there is definitely an upper bound to the rate of methane release possible. I therefore conclude that, to a first approximation, the way to think about land use and climate change is to think of the different possible *states* of areas of land as corresponding to different fixed net forcings. When you change the state of the land, it’s as if you’re adjusting a dial labelled ‘net forcing contribution’. But there are definite bounds on how far the dial can turn in either direction, something which is not the case with respect to machine emissions, the magnitude of which is instead limited only by fuel supply.

http://www3.interscience.wiley.com/journal/118961407/abstract

http://www.jennifermarohasy.com/blog/archives/Burrows%20PRA%20Talk%20-%20Sorting%20fact%20from%20fiction.doc

There are other forms of tree and shrub increase besides woodland thickening – shrub invasion, scrub encroachment and regrowth after land clearing. However they are all somewhat different. Woodland thickening which also occurs in southern Africa and the southern USA is thought to be the result of a fire-mediated sub-climax savanna woodland in which fire frequency has been reduced.

Put the system back in the “natural state” and you will have a lot fewer trees, and more grass (less carbon stored) and more fires – so more GHG emissions.

So for many parts of Australia – the case against domestic stock may be well overstated. Especially now that broadscale clearing of remnant vegetation is banned in Queensland and NSW.