365 Days of Climate Awareness 254 - The Cattle Industry and Climate Change

According to one estimate, methane (CH4, the primary component of natural gas) accounts for roughly 11% of the world’s annual greenhouse gas emissions. Over a 100-year period, methane is estimated to be 28-34 times as potent a greenhouse insulator as carbon dioxide; over a shorter time span of 20 years, that multiplier is 65. Breakdowns by sector vary, and this is where the details can become tricky, like for life cycle assessments of the greenhouse gas values of electric cars. To borrow an engineering term: how big a box to draw? That is, where to assign the system limits for which you must account?

Global greenhouse gas emissions by gas, 2018

Though annual global beef production, by tonnage, is roughly half that of pig meat and poultry, it dominates other livestock types in greenhouse gas emissions. This accounting involves elements such as the CO2 produced in manufacturing nitrate fertilizers for cattle feed, as well as direct production of methane by fermentation of manure and digestively by the cattle themselves. Unsurprisingly, wealthier countries–the United States, Europe, and other OECD (Organization for Economic Cooperation and Development) nations, plus Brazil and a few others–consume the most beef. Those nations’ diets therefore have much higher carbon footprints than others’ around the world.

Global methane emissions by source, 2018

Roughly 35% of overall greenhouse gas emissions are thought to result from global food production–all food sources, not simply beef. About 5000 km2/1930 mi2 of forests are lost per year (net–deforestation minus reforestation). Most of this is occurring in Brazil but it is a global issue. Land-use change–conversion from forest to pasture–is also a major source of agricultural greenhouse gas emissions.

Carbon footprint by food source

Global meat production by type

Within the slightly more than one-third of global greenhouse gas emissions which agriculture accounts for, in 2010 beef production was responsible for about 26.1% of the total, and cattle ranching for dairy was responsible for another 8.8%. Combined, nearly 35% of food-related greenhouse emissions results from cattle ranching. That is to say, 9% of global greenhouse emissions result from beef production, and 12% from beef plus dairy. Cattle ranching is easily the highest climate-impact global food source.

Per capita meat supply, 2017

Tomorrow: introduction to Chile.

Be brave, and be well.