Ruminant Livestock and Greenhouse Gases by Alan Broughton

Cattle Broughton

Within the climate change action movement there is a stream that places priority on reduction in livestock numbers as the key strategy to reduce greenhouse gases. I believe this is mistaken. The choice to not eat meat or other animal products should be regarded as a personal choice, not an ecological choice. There is no ecological justification for advocating a drastic reduction in livestock numbers as part of climate change mitigation. Efforts would be better spent in focusing on the real issues: energy generation, transport and the sustainability of farming systems. Livestock production can become an effective carbon sink with great potential to modify the greenhouse gas effect. The obstacle is not livestock but how the animals are managed.

There are many estimates of the contribution of livestock to human-caused greenhouse gases, ranging from 9% to 51%, depending on what is counted. The FAO estimated 18% in 2006 and then reduced it to 14.5% in a subsequent report. The higher figure, used by the anti-livestock lobby, includes animal respiration and other items which scientists say are not legitimate. However all these figures are gross figures, not net figures. When the carbon sequestration in grassland soils is taken into account, plus the consumption of ruminant-produced methane by soil bacteria, even the conventional grazing of cattle, sheep and goats provides a net greenhouse gas sink, unless nitrate fertilisers are used. With improved grazing management livestock are part of the solution to greenhouse gases.

Improved management means planned grazing systems in which large numbers of animals graze for a short time in a paddock, often only a few days, and do not return to that paddock until the pasture has completely recovered. In this system nitrate fertilisers are not used, soil organic carbon increases, costs are lower, erosion is prevented, soil absorbs rain and holds it longer, and production increases. Nitrate fertilisers are destructive of soil carbon, the mycorrhizal fungi that produce it, and the methane consuming bacteria. Reintroducing livestock into cropland and increasing the percentage tree cover on grazing land are additional carbon sequestration methods.

Effective action on any issue involves both personal decisions and political decisions, with political decision being of paramount importance. The cigarette smoking rate did not decrease because of personal decisions alone – it was because of a massive government-led campaign and a cessation of tobacco promotion. Ending the fossil fuel industry will not be due to people switching off their lights – government approval or non-approval of new coal mines and gas fields is what matters. Personal decisions can only have a marginal effect. Thus spending energy on promoting veganism is a diversion from the real campaign to reduce greenhouse gases, which is the substitution of fossil fuel energy by renewable energy.

(Alan Broughton, Vice-president, Organic Agriculture Association, Bairnsdale. A full copy of his paper with endnotes is available here.)