Demitarianism is the practice of making a conscious effort to reduce meat consumption for environmental reasons. The term is from the Latin dimedius: ‘from the middle’. The Demitarian diet aims to halve the portion of meat consumed in a regular meal, or to not eat meat on certain days. Demitarianism was developed in recognition of large scale animal farmings disruption of the nitrogen cycle with consequent effects on air, land, water, climate and biodiversity.1   

Food production and consumption, and the choices we make when we consume food, have flow-on effects for climate change. It is estimated that food production is responsible for more than a quarter of greenhouse gas emissions, of which up to 80% are associated with livestock production.Greenhouse gas emissions from meat production and other agricultural sectors are particularly significant for countries3 such as New Zealand and Argentina. Agriculture accounts for 49% of New Zealand’s emissions, the highest share in OECD (Organisation for Economic Co-operation and Development), countries. Between 1990 and 2014, New Zealand’s greenhouse gas emissions increased by 23%, and  – together with road transport and industry – the increase in intensive dairy farming has been a key factor in this.4

Greenhouse gas emissions due to meat production and other agricultural sectors in New Zealand include emissions from methane and nitrous oxides, plus carbon dioxide released from the tilling of soil. Methane is largely produced by the belching of livestock; nitrous oxide from animals urinating and the use of fertilizers. While methane is a powerful greenhouse gas, its lifetime in that atmosphere is around 8 to 9 years, unlike CO2, which lingers (about 19% of an emission made today will still be in the atmosphere in a thousand years’ time). Nitrous oxide (N2O) is also a long-lived gas. This lingering of CO2 and N2O in the atmosphere locks in warming on a much greater scale than the effect of methane.

Reaching a fossil-fuel-free world economy by 2050 will include transforming “the world’s food system from a major carbon emitter into a major carbon store.”5 As well as reducing greenhouse gas emissions from meat consumption this will also have the “advantage of easing pressure on land use”6, allowing  land to be used for reforestation efforts, which will be vital for negative emissions (carbon removal from the
atmosphere). Further, changing diets may be more effective than technological mitigation options for avoiding climate change,7 as strategies for protecting carbon-rich forests or adopting low-emission production techniques can increase land scarcity and production costs and push up food prices.

1. The term was established in 2009 in Barsac, France at the combined workshop of Nitrogen in Europe (NinE) and Biodiversity in European Grasslands: Impacts of Nitrogen (BEGIN), where they wrote: “The Barsac Declaration: Environmental Sustainability and the Demitarian Diet”.
2. ‘Analysis and valuation of the health and climate change co-benefits of dietary change,’in Marco Springmann, H. Charles J. Godfray, Mike Rayner, Peter Scarborough (eds.), Proceedings of the National Academy of Sciences United States, 113:15, 2016.
3. ‘Mitigation Update: Agriculture and Soil Management in the Spotlight’, Jennifer Allan, 23 March 2017.
4. New Zealand’s Greenhouse Gas Inventory 1990–2014. (Wellington: Ministry for the Environment, 2016).
5. Johan Rockstrom, ‘Why the World Economy Has to Be Carbon Free by 2050,’ The New York Times, 23 March 2017.
6. Springmann, et al., (2016) ibid.

7. Springmann, et al., (2016) ibid.