A wide range of methods to assess the impact of livestock activities on Climate Change (CC) at plot, farm, supply- chain, landscape, country or global levels does exist. The terms used in the literature can be confusing and are sometimes not used appropriately because a clear terminology is missing. We propose to distinguish two types of methodology on the basis of the most common used terminology: the “greenhouse gas (GHG) balance” and the “carbon (C) footprint”. This paper is based on a literature review of 235 scientific papers. “GHG and C balances” are based on an (eco)system approach. This methodology focuses on direct GHG emissions and C storage within the studied system boundaries. GHG balances focus on GHG emissions (CH4, N2O and CO2) when C balances consider both GHG emissions and C storage in soil and trees. This methodology is generally applied at plot, farm or landscape levels and results are generally expressed per unit of surface area. The “C footprint”, also referred as the “emission intensity”, is based on a life-cycle assessment approach. This methodology considers both direct and indirect GHG emissions and C storage, it encompasses emissions associated with i) raising animals, including enteric fermentation, ii) upstream activities (feed, fertilizers, and other inputs production, processing and transport) and iii) downstream processes (manure and waste management, post-farm transport, processing and packaging of raw animal products). This methodology is applied at supply-chain level and results are generally expressed per unit of livestock product. Differences in goals, functional units, scopes, level of analysis, system boundaries, sources of GHG emission measurements or calculation (simple emission factors or complex mechanistic simulation models), taking account or not C storage and other modelling assumptions make it impossible to compare assessment results of the two methodologies.