Well [member=2128]Womble[/member] that's the trouble, the only available stats are
not well researched. As I've mentioned before endlessly it's just not possible to measure an animals 'emissions' in a field setting. The conditions in a laboratory require the cow, sheep, goat whatever to be in an airtight 'room' with inputs and outputs measured, so they can't be eating grass which is their normal diet. I can't quote stats but I understand that being fed grain upsets the microflora/fauna of the rumen etc, so their output of products of digestion differ from those found in animals eating their normal natural diet.
Actually I've only ever seen research results for cattle so I can't say if the published figures have simply been extrapolated or if actual measurements have taken place for other ruminant species.
I have trawled through as much of the scientific papers as I can find online until my head was spinning and one thing stood out. Scientists themselves are questioning the accuracy of the published results. I saw quoted that one particular set of stats was found to be minus 62% to plus 300% representative of the actual rounded up result quoted - can't remember what for. Science acknowledges that it is indeed impossible to measure ruminants emissions in the field accurately, or even at all, and it seems no-one has tried!
The stats quoted don't take into account the sequestration of GHG's such as Methane, Nitrous Oxide and CO2 into sward, soil and trees/shrubs. Some of these are in the form of gaseous emissions but also as dung which decomposes directly on the ground and in a healthy system is taken back into the soil, to feed the next crop of grass, which is of course eaten by livestock again - all very circular and neat. In a lab, the dung is cleared away into a dung heap - do they measure the gases given off and include those in the calculations? Given that the UK does not include GHGs produced in international travel to and from the UK and for goods transport, nor the emissions generated by other countries in manufacturing and producing goods for our consumption, including wood for wood chip boilers from virgin forests, nor the GHGs produced by our rubbish exported to other countries for disposal, as part of our own GHG emissions, then probably not. Drax power station is judged to be carbon neutral or nearly so because the wood it uses comes from overseas and we merrily ignore the destruction of non-coppiced source forests and the vast transport costs to bring it here. So green.
I think the only activity the official stats support, is for those lucky ruminants chosen to be shut in a lab box to have their emissions measured! A worldwide rural industry, that of raising meat to feed our population of 7.5 billion and growing, is under threat, with a perhaps unintended consequence of mass starvation when the big bods discover that you truly cannot grow veggies on a mountain
So what damage are we doing to our environment by growing food on our land? I feel that it's no more than we do by simply being alive and living. Listening to people chatting on TAS I think most of us don't pour on the chemicals, we don't overstock, we don't keep caged birds and feed-lot cattle, our sheep live extensively as do our cattle and goats, and our buffalo. If humans were not here, there would still be animals on the land producing some emissions, which would be sequestrated into the ground and the vegetation and recycled into that ecosystem. As smallholders we try to emulate that way. Some of us produce a bit of excess and we sell that on - I'm not sure where that fits in the equation.
Having met people in other areas of the world who keep livestock, I see that their methods are similar too. They keep animals on land which is suitable for them and without humans would have a similar type and density of animal occupation.
The damage to the environment is caused by cutting down our forests and draining our wetlands to feed our greed for enormous and frequent portions of cattle meat. A pound of steak at a sitting? That is greed pure and simply totally unnecessary.
I can't quote figures for you - I have seen a selection enough to suggest to me that a whole load of pertinent and well executed scientifically accurate research still needs to be done, before we destroy our earth systems even more in our efforts to improve.
I would be delighted to see any results you can find womble.
