PurposeBioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers.MethodsThe review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policy-facing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy.Results and discussionThe credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance.ConclusionsThe emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large.

中文翻译：

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LCA 在环境决策中面临的挑战集群——我们可以从生物燃料中学到什么

目的生物能源越来越多地用于帮助实现温室气体 (GHG) 和可再生能源目标。然而，生物能源的可持续性受到质疑，导致越来越多地使用生命周期评估 (LCA)。生物能源系统是全球性的和复杂的，市场力量可能导致与 LCA 和政策相关的重大变化。本文的目的是说明与 LCA 相关的复杂性，特别关注生物能源和相关政策制定，以便其使用可以更有效地为政策制定者提供信息。方法审查基于一系列以生物能源生命为重点的研讨会的结果周期评估。专家提交的意见在前两个研讨会中进行了汇编和分类。出现了 100 多个问题。考虑到列表中的冗余和相似之处，这减少到大约 60 个挑战，其中许多是密切相关的。然后在英国伦敦的面向政策的研讨会上进一步探讨了其中一些问题。作者采用严格的方法对生物燃料/生物能源 LCA 和政策交叉点的挑战进行分类。结果和讨论 LCA 的可信度是其在政策中使用的核心。即使是符合 ISO 标准以及政策和监管工具的 LCA，也为解释和灵活性留下了很大的空间。在生物能源领域，这导致了挫败感，有时缺乏明显的方向。本文确定了主要挑战群：总体问题、应用和实践以及价值和道德判断。其中许多反映了从应用 LCA 评估单个产品或系统到越来越普遍的更广泛方法的转变。由于分配问责制方面的挑战，影响评估的不确定性极大地影响了规划和合规性，并且传达生物能源内部固有的复杂性和不确定性变得越来越重要。结论 LCA 在生物能源治理中的出现特别重要，因为其他部门可能会过渡到类似的领域治理模式。LCA 正在被拉伸以适应复杂和广泛的政策相关问题，寻求纳入对长期可持续性具有重大影响的外部性。随着政策越来越依赖 LCA，对方法论施加的压力正变得更加清晰和阻碍。