Companies typically use databases such as the Evoinvent and Gabi TS for materials and products emission factors or information from CDP supplier databases and Ecovadis ratings to prepare their emissions inventory . Although these cover a wide range of materials , products , and services , companies may not be able to find all emissions factors they need to have a complete inventory of greenhouse gases . It would , of course , be ideal if suppliers provided the specific data , but not all suppliers will be able to support such requests . It is most likely that a company will have to use a hybrid approach : a combination of a spending-based method ( using financial data to calculate estimated emissions , for example ), an average data method ( converting volume of purchased goods to emissions estimates ), and supplier-specific method ( using actual life cycle analysis to calculate emissions , for example ). While this hybrid method may not be fully accurate , it helps to identify the biggest sources of upstream value chain emissions with sufficient accuracy to start engaging in the joint management of emissions reductions .
Refine supplier base
Companies should identify the suppliers with the greatest estimated potential to reduce emissions . They are the first targets to engage , and the easiest wins occur when the company has a strong buying position – lots of influence , in other words – and the supplier has strong emissions reduction potential . Where the company ’ s influence is high but the potential for the supplier to actually effect reductions is low , it can begin joint initiatives to reduce and replace the input materials or services in question . Where there is low influence over the supplier and low potential of reduction , switching suppliers and / or redesigning the product might be the right move . Where there is high potential for the supplier to reduce emissions , but the company has little influence over the supplier , it may want to collaborate with other customers to improve sustainability . Of course , when forging these alliances , all parties must be careful to avoid any potential competition law breach . Once a company has mapped out and prioritized suppliers , it should engage with them to receive primary data .
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