Food, energy and water: this is what the United Nations refers to as the ‘nexus’ of sustainable development. As the world’s population has expanded and gotten richer, the demand for all three has seen a rapid increase. Not only has demand for all three increased, but they are also strongly interlinked: food production requires water and energy; traditional energy production demands water resources; agriculture provides a potential energy source. 

The most important insight from this study: there are massive differences in the GHG emissions of different foods: producing a kilogram of beef emits 60 kilograms of greenhouse gases (CO2-equivalents). While peas emits just 1 kilogram per kg.

Overall, animal-based foods tend to have a higher footprint than plant-based. Lamb and cheese both emit more than 20 kilograms CO2-equivalents per kilogram. Poultry and pork have lower footprints but are still higher than most plant-based foods, at 6 and 7 kg CO2-equivalents, respectively.