Food and Agriculture – Public health benefits of reduction in greenhouse-gas emissions.

80% of agricultural emissions arise from Livestock – methane and nitrous oxide.

Agriculturally-induced change in land use – deforestation, overgrazing, and conversion of pasture to arable land – accounts for a further 6 – 17% of global greenhouse gas emissions. 50% of food-related greenhouse-gas emissions are generated during farming. These include nitrous oxide and methane from livestock, carbon dioxide from deforestation especially; Nitrous oxide comes from pasture land and arable land used to grow feed crops and methane from the gut of ruminant animals such as cattle and sheep. Pork chicken and eggs produce less CO2 and are more efficient at feed conversion.

Livestock provides a large amount of saturated fats which are a risk factor for cardiovascular disease.

For the UK, the government agreed target reduction in emissions is that the baseline levels recorded in 1990 are lowered by 80% by 2050. This requires a 50% reduction by 2030. To achieve this in the UK will require technology improvements and a 30% reduction in livestock population. If this target is achieved, it will reduce coronary heart disease by 15% in the UK alone. This is quantifiable as 2850 disability-adjusted life-years (DALYs) per million in 1 year. This strategy will meet cultural nutritional and commercial resistance. In Sao Paulo, Brazil, achieving targets will result a 16% reduction in coronary rate and a positive gain of 2180 DALYs per million in 1 year.

By 2030, rising demand for meat will drive up livestock production by 85% from 2000 levels. Processed farm foods also use fossil fuels for production. Animals are currently an important source of protein, energy, and nutrients such as iron, calcium, vitamin B12 and zinc. Cattle and sheep can use marginal land unsuitable for growing cereals and soy crops and are best used in that manner. Soy and cereals should best be consumed directly by humans and not via poultry production.

The bottom line must be to change to affordable, healthy, low-emission diets for all societies. Pricing, regulation, taxation and labelling are parts of the strategy. That is some challenge. In world terms, China and India will be huge problems.

There is a series in the Lancet on Health and Climate Change which is well written , detailed and referenced – December 2009.