Impact of Dietary Meat and Animal Products on GHG Footprints: The UK and the US

Abstract

Direct and indirect greenhouse gas (GHG) emissions from the ~30+ billion animals consumed as food each year contribute ~14–16% of the global total. The aim of this research is to determine the contribution of meat and animal products to individual GHG footprints. Top-down estimates of GHG emissions from each livestock species are determined using livestock numbers, types, and region-specific emission factors. Comparing livestock emissions with those from individual countries, cattle rank as the third largest emitter after China and the United States (US). The largest uncertainty in these emissions calculations is in the range of emissions factors. Global top-down calculations indicate that the per capita GHG footprint from livestock emissions alone are approximately 1 tCO2eyr−1. For the United Kingdom (UK) and the US, the calculated GHG livestock-related footprints are 1.1 tCO2eyr−1 and 1.6 tCO2eyr−1 per person, respectively. Bottom-up calculations focused on the UK and the US from consumption figures indicated emissions related to meat consumption are approximately 1.3–1.5 tCO2eyr−1 per person. Comparing dietary changes with other ways of reducing GHG footprints indicates removing dietary meat is similar to avoiding one long-haul flight each year and a larger reduction than driving 100 miles less each week.