Center for Industrial Ecology, Yale School of the Environment, Yale University, 380 Edwards Street, New Haven, Connecticut 06511, United States.
Environ Sci Technol. 2022 Jan 18;56(2):1395-1404. doi: 10.1021/acs.est.1c05923. Epub 2021 Dec 6.
Global warming potential (GWP) has been widely used in the life cycle assessment (LCA) to quantify the climate impacts of energy technologies. Most LCAs are static analyses without considering the dynamics of greenhouse gas (GHG) emissions and changes in background GHG concentrations. This study presents a dynamic approach to analyze the life-cycle GWP of energy technologies in different timeframes and representative GHG concentration pathways. Results show that higher atmospheric GHG concentrations lead to higher life-cycle GWP for long-term analysis. The impacts of background GHG concentrations are more significant for technologies with large operational emissions or CH emissions than technologies with low operational emissions. The case study for the U.S. electricity sector in 2020-2050 shows the impacts of background GHG concentrations and different LCA methods on estimating national climate impacts of different energy technology scenarios. Based on the results, it is recommended for future LCAs to incorporate temporal effects of GHG emissions when (1) the technology has large operational GHG emissions or CH emissions; (2) the analysis time frame is longer than 50 years; (3) when LCA results are used for policymaking or technology comparisons for mitigating climate change.
全球变暖潜能值（GWP）已广泛应用于生命周期评价（LCA）中，用于量化能源技术的气候影响。大多数 LCA 是静态分析，没有考虑温室气体（GHG）排放的动态变化和背景 GHG 浓度的变化。本研究提出了一种动态方法，用于分析不同时间范围内和代表性 GHG 浓度路径下能源技术的生命周期 GWP。结果表明，较高的大气 GHG 浓度会导致长期分析的生命周期 GWP 更高。对于具有较大运营排放量或 CH 排放量的技术，背景 GHG 浓度的影响比具有较低运营排放量的技术更为显著。以 2020-2050 年美国电力部门为例，说明了背景 GHG 浓度和不同 LCA 方法对估计不同能源技术情景下国家气候影响的影响。基于这些结果，建议未来的 LCA 在以下情况下考虑 GHG 排放的时间效应：(1) 技术具有较大的运营 GHG 排放或 CH 排放；(2) 分析时间框架超过 50 年；(3) 当 LCA 结果用于决策制定或气候变化缓解的技术比较时。
