Prospective Characterization Factors for Assessing Climate Change Impacts in Life Cycle Assessments

Prospective life
cycle assessment (pLCA) is a future-oriented approach
that estimates the environmental impacts of products and systems under
future technological changes, market dynamics, and policy shifts.
However, pLCA lacks consistent prospective characterization factors
(pCFs) to assess the climate impacts of future emissions and align
the inventory and impact assessment phases. This work produces pCFs
by integrating gas-specific climate parameters with future emission
scenarios from the Integrated Assessment Models (IAM). Prospective
Global Warming Potential (pGWP20, pGWP100) and
Global Temperature change Potential (pGTP50, pGTP100) are computed for emission years until 2050. Relative to present-day
CFs, methane pGWP100 varies from −8% to +23%, and
nitrous oxide varies from −17% to +7%. CH4 pGTP100 shifts from −24% to +22%, while N2O pGTP100 shifts from −27% to +8%. For non-CO2-dominated
activities such as rice production, climate impacts increase by 8%
in terms of pGWP100. With pGTP100, impacts of
ammonium nitrate decrease by 9%. When pCFs are combined with prospective
background inventories, impacts are substantially lower in sectors
such as steel (−44%), road transport (−58%), and cement
(−31%) under pGTP100. Overall, the availability
of pCFs for multiple climate metrics and IAM scenarios enables a consistent
coupling of impact assessment with future-oriented inventory data,
improving the robustness and coherence of pLCA.

展望性生命周期评估（Prospective life cycle assessment, pLCA）是一种面向未来的研究方法，用于估算产品与系统在未来技术变革、市场动态及政策变动下的环境影响。然而，当前pLCA缺乏统一的展望性特征化因子（prospective characterization factors, pCFs），无法用以评估未来排放的气候影响，也难以实现清单与影响评估阶段的协同一致。本研究通过将气体特异性气候参数与综合评估模型（Integrated Assessment Models, IAM）生成的未来排放情景相结合，构建了相应的pCFs。研究计算了截至2050年各排放年份的展望性全球增温潜势（Prospective Global Warming Potential, pGWP20、pGWP100）与展望性全球温度变化潜势（Global Temperature change Potential, pGTP50、pGTP100）。相较于当前的特征化因子，甲烷的pGWP100波动范围为-8%至+23%，一氧化二氮的pGWP100波动范围为-17%至+7%；甲烷的pGTP100波动范围为-24%至+22%，一氧化二氮的pGTP100波动范围为-27%至+8%。针对水稻种植等非二氧化碳主导的活动，其pGWP100对应的气候影响提升了8%；而采用pGTP100时，硝酸铵的气候影响降低了9%。当将pCFs与展望性背景清单相结合时，在pGTP100框架下，钢铁、道路运输与水泥等行业的气候影响分别降低了44%、58%与31%。总体而言，针对多种气候指标与IAM情景的pCFs的问世，实现了影响评估与面向未来的清单数据的统一耦合，提升了展望性生命周期评估的稳健性与一致性。