Comparison of “CO2 efficiency” between company and industry

The concept of eco-efficiency, product or service value per environmental influence, was applied to define “total CO2 efficiency”, “direct CO2 efficiency” and “indirect CO2 efficiency” using Input-Output (I-O) table analysis for the evaluation of companies and industries. The result shows that the analysis of the efficiency was useful to characterize industries according to CO2 efficiency. The comparison of company-based CO2 efficiency against I-O-based CO2 efficiency was possible for beer companies and petroleum companies because they almost completely belong to a single type of industry sectors. However, generally such comparison was difficult for the companies that belong to many industry sectors. Therefore, we proposed the new method “integrated CO2 efficiency index for company evaluation (ICEICE)” which makes it possible to compare the environmental performances of all the companies regardless of the number of industry sectors they belong to.