Rethinking the paper product carbon footprint accounting standard from a life-cycle perspective

Paper products are carbon-intensive and having a huge potential for carbon reduction due to their biomass-oriented characteristics. A uniform standard for total carbon footprint (CF) accounting is vital. However, the existing standards have not yet been unified. Inconsistencies between standards cause difficulties in their use and significantly weaken the credibility and comparability of the carbon footprint of a product (CFP). This work rethought the three most widely used standards (Publicly Available Specification 2050 (PAS2050), Product Life Cycle Accounting and Reporting Standard (GHG Protocol), and Product Life Cycle Accounting and Reporting Standard (ISO14067)) from the life-cycle perspective, and established a more appropriate and comprehensive CF accounting standard for paper products (CFASPP). Sanitary pads were selected as a case study to illustrate the discrepancies between PAS 2050, the GHG Protocol, ISO 14067, and CFASPP, for which the annual production CF results were 1424.60, 1481.08, 1453.57, and 1427.04 tons of carbon dioxide equivalent (CO2e) respectively. The main reasons for the different CF results were the cut-off criteria and the inclusion or exclusion of carbon storage, delayed emissions, and energy recovery. Each element increased or decreased 22.57 (carbon storage), 29.96 (cut-off criteria), 10.4 (delayed emissions), and 27.52 (incineration with energy recovery) tons of CO2e in the results. With increasing demand, these discrepancies will become increasingly significant and may lead to corporations shouldering more or less carbon emission responsibilities by selecting different standards, which will challenge the fairness of product carbon neutrality management. CFASPP covers all paper product life-cycle stages and places greater emphasis on the aspects of carbon storage, delayed emissions, and energy recovery in incineration, which cannot be ignored for the CF accounting of paper products and other biomass-oriented products. This study aims to provide a more applicable and comprehensive guide for corporations to evaluate the CF of paper products, and to provide a reference for the construction of a carbon-neutral evaluation system.