Recognizing the existence of this kind of bottleneck, international guidelines on the assessment of lifecycle GHG emissions permit companies to utilize data from similar firms in lieu of actual data (e.g. the carbon numbers for glass from another nation or firm). But the specification prohibits such "second-tier numbers" from accounting for more than 10 % of a product's lifecycle carbon emissions.
遇到這種瓶頸，目前產品碳足跡準則允許廠商可以用同性質的產業資料庫數據代替（例如以別國或別家企業的玻璃碳排數據計算），但這種「次級數據」不能使用在碳排放量超過整個產品生命週期碳足跡 10 % 的環節上。