Is New Zealand grass-fed lamb and beef better for the climate than indoor, grain-fed production systems in other parts of the world? Can ‘sus‍‍‍tainable’ grazing practices really help to store carbon within the soil, and if so, could this help to counterbalance livestock’s significant contribution to climate change?

No and no- are the resounding answers, according to the most recent report by the University of Oxford offshoot the Food Climate Research Network. The report, entitled Grazed and confused?, aimed to clear up the confusion currently surrounding grass-fed beef and its contribution to climate change.

1. Soil Carbon Sequestration

The Debate: Soil carbon sequestration is just a fancy name for storing carbon in the soil. It is argued that careful grazing of livestock can a‍‍‍id this process, thereby helping to reduce atmospheric CO2 and mitigate climate change. The below table summarises the debate:

Grass-Fed Beef is No Solution: It's the Problem‍‍‍

Planetary Health

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©  2016, Plant Based Living ‍‍‍Initiative

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The Grass-fed Debate

There has been a lot of noise and not a lot of scientific evidence.

Allan Savory, a proponent of ‘holistic’ grazing, would have you believe that livestock are in fact the solution to climate change. Graham Harvey, author of Grass-Fed Nation, claims that all of the carbon dioxide released into the atmosphere since the beginning of the industrial revolution could be absorbed by grazing ruminants on the US prairies alone.

Paleo and high-fat diet advocates, desperate for ways to justify the environmental implications of their eating choices, have latched onto such ideas. Zoe Harcombe, thinks that Harvey’s book is ‘beautifully written’, and this information has trickled down‍‍‍ to NZ’s Chief Health and Nutrition Education Advisor, Grant Scofield. Tim Noakes, who writes the forward to Schofield's high-fat diet book, told the Huffington Post that eating meat is "the only way we will save the planet."

Clearly some people are very confused, but what is the crux of the debate, and which side does the evidence weigh in on?‍‍‍

Author: Jon Drew

Jon is a founding member of PBLI and a fourth-year medical student at the University of Otago, in New Zealand. He is currently completing an honour's degree focused on eating patterns that are both healthy and sustainable.

The Verdict: Soil carbon sequestration from good grazing management cannot offset livestock emissions, nor is it the solution to climate change as Allan Savory would have you believe.

According to the FCRN report, soil carbon sequestration could offset anywhere between 20-60% (the upper range being rather ambitious) of emissions from grazed, as opposed to grain-fed, livestock- a far cry from Savory’s unsubstantiated promises.

This benefit is diminished by the fact that grazing systems, like those in NZ, are generally known to be less productive and are, as a consequence (and contrary to what most people believe), actually more harmful to the climate than intensive grain-fed systems (i.e. emissions per unit meat output are higher).

Soil carbon sequestration is like sweeping climate change under the rug: any future change in grazing practice- perhaps as the result of a drought- could cause stores to be released.

A recent ground-breaking publication in the academic journal Science found that, in response to warming temperatures, soil microbes produce more carbon, which in turn causes soil carbon stores to be depleted. Soils releasing their carbon stores in response to global warming could trigger a dangerous feedback l‍‍‍oop, which on “a global-scale…could be very difficult, if not impossible, to halt."

We ought to be focused on reducing emissions in the first place, not trying to hide a tiny proportion of them in the ground afterwards.

2. Land-use Requirements

The Debate: Unlike grain-fed anim‍‍‍als or monoculture plant crops, grass-fed ruminants do not cause substantial land-use change, especially if they are grazed on grasslands unsuited to growing crops. Again, the debate is summarised in the below table:

Final Remarks

The authors of the FCRN report conclude that there is limited place for‍‍‍‍‍‍ grazing livestock in a sustainable food system: ‍‍‍

“(w)hichever way one looks at it, and whatever the system in question the anticipated continuing rise in production and consumption of animal products is cause for concern. With their growth, it becomes harder by the day to tackle our climatic and other environmental challenges.”

The Verdict: Growing the grass-fed livestock sector is no solution.

Replacing grain-fed systems with grass-fed ones is simply infeasible: existing grasslands are not large enough to support current consumption of animal protein globally, while meeting the projected future demand for meat from grazing systems would require catastrophic conversion of forests into grassland.

Furthermore, the assumption that grass-fed lamb and beef use ‘spare’ land that has no other use is misguided. Very few of the world’s grasslands today are natural: most exist as a consequence of devastating environmental destruction of forests in the past. We should remember that clearing land for grazing livestock has his‍‍‍torically been the principle cause of this destruction.

“(L)and that is used to graze animals could potentially be used for something else – for food, for nature conservation, for forests, or for bioenergy,”‍‍‍ write the authors of the FCRN report, “(t)here are almost always alternatives: the question is, what do we want?”

‍‍‍Figure: New Zealand's forests (black) over time (pre-settlem‍‍‍ent to mid-1970s)