Carbon emission is calculated based on total activity data ( I AD i , expressed in units presented in Table 2) multiplied by the corresponding emission factors ( I EF i s), leading to a GHG emission output, expressed in gram (g), kilogram (kg), or metric tonne (t) of CO SB 2 sb equivalent (CO SB 2 sb e). A carbon footprint is defined by the Carbon Trust as "the total set of GHG emissions caused directly and indirectly by an individual, event, organization or product, expressed as carbon dioxide equivalent (CO SB 2 sb e)" [5]. Medical gas emissions (related to release of carbon dioxide) accounted for 11 kg CO SB 2 sb e. Discussion This is the first study to estimate the carbon footprint of GIE based on a multi-criteria analysis. Method of carbon footprint calculation The Bilan Carbone method evaluates direct GHG emissions resulting from activities that an organization controls (scope 1), emissions from energy use (scope 2), and indirect emissions from products and services an organization does not directly control (scope 3; Fig. [Extracted from the article]