Lamb vs Dried beans
Lamb is second only to beef on emissions and first on land use per kilogram in many systems. Beans occupy the opposite end of every axis, and they are the cheapest protein per gram on the shelf.
Per per kg of food
Greenhouse gaseskg CO₂e / kg
Lamb
39.7
Dried beans
1.8
Land usem² / kg
Lamb
369
Dried beans
15.6
Freshwater withdrawalL / kg
Lamb
1803
Dried beans
1200
Fibreg / 100 g
Lamb
0
Dried beans
15
Source: Poore & Nemecek (2018), Science · Our World in Data · USDA FoodData Central
Verdict
Beans cut emissions about 22-fold and add fibre lamb cannot provide.
Questions people ask
Why do sheep have such a big footprint?
They are ruminants, so they emit methane, and they convert feed to meat inefficiently while grazing extensive land.