In early June of 2018, the Guardian covered a recent article by Poore and Nemecek in Science. The Guardian coverage includes a graphic which states that farmed animal products contribute 58 percent of GHG gases. However, what isn’t made clear is that this is 58 percent of the GHG gases that are attributable to the food supply chain. This is made clear in the article by Poore and Nemecek, which states
“In particular, the impacts of animal products can markedly exceed those of vegetable substitutes (Fig. 1), to such a degree that meat, aquaculture,
eggs, and dairy use ~83% of the world’s farmland and contribute 56 to 58% of food’s different emissions, despite providing only 37% of our protein and
18% of our calories.” (pg. 4)
The authors further note
“Today’s food supply chain creates ~13.7 billion metric tons of carbon dioxide equivalents (CO2eq), 26% of anthropogenic GHG emissions.” (pg. 1)
This implies that animal products in the food supply chain account for approximately 15 percent of total anthropogenic emissions.