Perceived uncertainties of characterization in LCA: a survey
Perceived uncertainties of characterization in LCA: a survey
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LCA 表征的感知不确定性：一项调查
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
S. Suh
中科院分区：
文献类型：
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作者：
Yuwei Qin;S. Cucurachi;S. Suh
生命周期评估(LCA)文献中的不确定性分析主要集中在生命周期清单(LCI)阶段，但LCA专家普遍认为，生命周期影响评估(LCIA)阶段可能会对LCA结果的总体不确定性造成更大影响。然而，与LCI相比，表征中感知到的不确定性的大小还没有在文献中得到检验。在这里，我们使用系谱方法来衡量在表征阶段相对于LCI阶段的感知不确定性。此外，我们还评估了对系谱方法的认可程度，将其作为表征生命周期评价不确定性的一种手段。将数字单位扩散评价谱(NUSAP)方法应用于环境风险评价文献，提取了表征阶段不确定性的评价标准。我们使用专家启发来确定专家库，并进行了一项调查，来自12个国家的47名LCA从业者对此做出了回应。为了减少个人在感知几何标准差(GSD)值上的偏差，我们使用了两个关于出生时体重和预期寿命的参考问题进行校准。近一半(49%)的受访者表示赞成将谱系矩阵方法作为表征生命周期评价中不确定性的一种手段，并且对受访者对谱系矩阵的熟悉程度高度敏感。例如，对血统矩阵非常熟悉的受访者更加两极分化，分别有15%和19%的受访者表示强烈赞成或强烈反对。不太熟悉系谱方法的受访者通常更倾向于使用它。与LCI相比，特征因子的变异性受地理相关性和基础模型可靠性的影响更大，与LCI的可比标准相比，平均GSD高出11%至16%。相反，与LCI相比，时间相关性标准是表征的一个不太重要的因素。总体而言，调查受访者认为LCIA的定性只比LCI的不确定性略高，但在定性方面的反应比LCI的差异更大。这一发现表明，需要进行更多的研究，以制定更全面的方法，以确定生命周期影响评估中的不确定性，使其与LCI中的不确定性衡量标准相兼容。
Uncertainty analyses in life cycle assessment (LCA) literature have focused primarily on the life cycle inventory (LCI) phase, but LCA experts generally agree that the life cycle impact assessment (LCIA) phase is likely to contribute even more to the overall uncertainty of an LCA result. The magnitude of perceived uncertainties in characterization relative to that in LCI, however, has not been examined in the literature. Here, we use the pedigree approach to gauge the perceived uncertainty in the characterization phase relative to the LCI phase. In addition, we evaluate the level of approval on the pedigree approach as a means to characterize uncertainty in LCA. Applying the Numeral Unit Spread Assessment Pedigree (NUSAP) approach to environmental risk assessment literature, we extracted the criteria for evaluating the uncertainty in the characterization phase. We used expert elicitation to identify a pool of experts and conducted a survey, to which 47 LCA practitioners from 12 countries responded. In order to reduce personal biases in perceived geometric standard deviation (GSD) values, we used two reference questions on weight and life expectancy at birth for calibration. Nearly half (49%) of respondents expressed their approval to the pedigree matrix approach as a means of characterizing uncertainties in LCA, and responses were highly sensitive to the respondent’s familiarity with the pedigree matrix. For instance, respondents who are highly familiar with the pedigree matrix were more polarized, with 15% and 19% of them expressing either strong approval or strong disapproval, respectively. Respondents less familiar with the pedigree approach were generally more favorable to its use. Compared with LCI, variability in characterization factors was influenced more strongly by geographical correlation and reliability of the underlying model, which showed 11 to 16% larger average GSDs when compared with the comparable criteria for LCI. Conversely, temporal correlation criterion was a less significant factor in characterization than in LCI. Overall, survey respondents viewed LCIA characterization as only marginally more uncertain than LCI, but with a wider variability in responses on characterization than LCI. This finding indicates the need for additional research to develop more thorough methods for characterizing uncertainties in life cycle impact assessment that are compatible with the uncertainty measures in LCI.