Report: Climate impact of cutting back on cattle questioned

cowA report presented this week at the 239th National Meeting of the American Chemical Society suggests that despite claims to the contrary, eating less meat and dairy will not have much of a mitigating impact on climate change.

That’s because in most developed countries, greenhouse gas emissions from livestock make up a small percentage of overall emissions compared to transport, the energy sector and industry.

On the other hand, land-use changes in developing countries from forest to pasture are contributing to global warning says the report’s lead author, UC Davis scientist Associate Professor Frank Mitloehner, and significant reductions of carbon sequestering forests will have “large effects on global climate change”.

“The fact that land-use changes associated with livestock (i.e., forested land converted to pasture or cropland used for feed production) are a significant source of anthropogenic GHGs in Latin America and other parts of the developing world is apparent,” he writes.

“However, it is likely that any kind of land-use change from the original forestland will lead to great
increases in global warming.”

Rather than cutting dairy and meat production, says Dr Mitloehner, the correct strategy should be not less farming, but smarter farming, with the developed world helping the developing world to adopt production strategies designed to produce food more efficiently – and cut down on greenhouse gas emissions.

“Modern livestock production has experienced a marked improvement of efficiencies, leading to significantly decreased numbers of animals to produce a given amount of product that satisfies the nutritional demands by society,” he writes.

New Zealand’s GHG emissions profile has been described as being more like that of a developing nation’s with nearly 50 per cent of emissions attributed to the agricultural sector.

The SMC asked local experts for feedback on the report – further comments will also be added as the come in.

Please note: this report can be accessed by registered journalists via the SMC Resource Library.

Associate Professor Jonathan Hickford, of the Faculty of Agriculture and Life Sciences at Lincoln University, comments:

“In the NZ context, something has to eat the grass that grows so prolifically across about 45% of the total area of NZ. Of the productive animals, only ruminants can do this.

“Lord Stern [writing in the Stern Report] seemed to miss the point that ruminants (sheep and cows) produce food we can eat by eating something we can’t (grass), when pigs and chickens (monogastrics) tend to eat the same food (minus a bit of quality?) that we humans eat.

“Here’s a statement that summarises things nicely:

“”To be successful, all agriculture depends on the land resource and the prevailing climate conditions. Around 60 per cent of UK farmland is only suitable for growing grass; it would not support a crop directly consumable by humans. Without a grazing animal you could not use this land resource to produce food for the population. Globally, the same story is repeated. Therefore the challenge is to get the best food returns from the available land while minimising water usage and other environmental impacts, such as GHG emissions.”

“I guess the bottom line is that if you are going to feed the world’ s population effectively, then you need to produce sufficient food.  We are probably all over-nourished in the west, the irony being that most Western-world populations are in decline, while at least a billion people are starving, yet they live in countries with rapidly growing populations.  I suspect that if the whole world stopped eating meat of any kind (good for GHG), demand for vegetarian food would increase and the starving masses would be even hungrier.  There would also be mass privation and war, history setting a sound precedence for this.   We might drop GHG’s by 18% – if that figure is correct – but at what cost.”

Professor Jacqueline Rowarth, Director of Massey Agriculture at Massey University, comments:

“Concern about food production is facilitating polarisation of what is already an emotive debate, started by the cry to ‘save the world’. Emotions run high in those that are ideologically driven, and certainly there are some in the vegetarian, vegan and organic camps that believe very strongly that theirs is the way for global survival.

“The Life Cycle Assessment (LCA) for livestock gives not only data from cradle to grave for livestock (and in doing so shows how very complex such calculations are), but also suggests what comparisons should be made in LCA to determine where a sustainable food production future might lie. It does not, however, and perhaps wisely, give the answer… as ‘sustainability’ depends on so many different underlying factors.

“The Ministry of Agriculture and Forestry has supported the establishment of the NZ Life Cycle Management Centre – a collaboration between Massey University, AgResearch, Landcare Research, Plant & Food Research and SCION – to build capability in Life Cycle Management by providing education, training and research. This initiative, as well as the paper on LCA in livestock, are timely.

“Many of the calculations in the LCA for livestock paper will need adjustment for New Zealand conditions and systems. We need more people who understand the issues not only to do these calculations and create a sustainable future, but also to assist in explaining the outcome of those calculations on farm (so that systems and processes can be adapted appropriately) and in society in general (to allay the concerns that lead to polarisation).”

Dr Jon Tanner, CEO of Organics Aotearoa New Zealand, comments:

“We need to avoid a western paradigm. Farmers in developing countries (where livestock make a major contribution to emission profiles) keep animals for a wide variety of reasons.  Production of milk and meat may come in a very poor second to the importance of keeping animals for savings, offsetting risk, draught power and manure – particularly in the poorest households where livestock may be the only means to a livelihood.  Encouraging lower levels of meat and dairy consumption in these countries (if that were possible) may not then result in smaller number of animals being kept.”

Further Information

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