Greenhouse gas emissions have been quantified for 11 Norwegian salmon supply chains. This is the third comprehensive assessment carried out for the Norwegian farmed salmon supply chains with some differences in the data used and the method chosen. Hence results presented in this report must be compared keeping in mind the differences and changes in the GHG emissions cannot be interpreted as a direct result of aquaculture industry's reduction measures. Greenhouse gas emission reduction potential of 19 improvement measures including changes in feed composition, distribution to the market, reduced losses and electrification of grow-out farms among others was quantified. The effects of the measures vary from 19% lower emission to 29% higher emissions than the base case farmgate salmon at 3.8 kg CO2e/kg liveweight. The analysis is mainly based on the LCA method while Environmentally Extended Input-Output method is used as a supplementing method. The present study is carried out in a collaboration between SINTEF Ocean AS, Asplan Viak AS and RISE Research Institutes of Sweden.