The methods for assessing the impact of using abiotic resources in life cycle assessment (LCA) have always been heavily debated. One of the main reasons for this is the lack of a common understanding of the problem related to resource use. This article reports the results of an effort to reach such common understanding between different stakeholder groups and the LCA community. For this, a top-down approach was applied. To guide the process, a four-level top-down framework was used to (1) demarcate the problem that needs to be assessed, (2) translate this into a modeling concept, (3) derive mathematical equations and fill these with data necessary to calculate the characterization factors, and (4) align the system boundaries and assumptions that are made in the life cycle impact assessment (LCIA) model and the life cycle inventory (LCI) model. We started from the following definition of the problem of using resources: the decrease of accessibility on a global level of primary and/or secondary elements over the very long term or short term due to the net result of compromising actions. The system model distinguishes accessible and inaccessible stocks in both the environment and the technosphere. Human actions can compromise the accessible stock through environmental dissipation, technosphere hibernation, and occupation in use or through exploration. As a basis for impact assessment, we propose two parameters: the global change in accessible stock as a net result of the compromising actions and the global amount of the accessible stock. We propose three impact categories for the use of elements: environmental dissipation, technosphere hibernation, and occupation in use, with associated characterization equations for two different time horizons. Finally, preliminary characterization factors are derived and applied in a simple illustrative case study for environmental dissipation. Due to data constraints, at this moment, only characterization factors for “dissipation to the environment” over a very-long-term time horizon could be elaborated. The case study shows that the calculation of impact scores might be hampered by insufficient LCI data. Most presently available LCI databases are far from complete in registering the flows necessary to assess the impacts on the accessibility of elements. While applying the framework, various choices are made that could plausibly be made differently. We invite our peers to also use this top-down framework when challenging our choices and elaborate that into a consistent set of choices and assumptions when developing LCIA methods.

中文翻译：

---

LCA 中资源使用的自上而下表征：从资源使用的问题定义到元素耗散到环境的操作表征因素

在生命周期评估 (LCA) 中评估使用非生物资源的影响的方法一直备受争议。造成这种情况的主要原因之一是对与资源使用相关的问题缺乏共识。本文报告了在不同利益相关者群体和 LCA 社区之间达成这种共识的努力结果。为此，采用了自上而下的方法。为了指导这一过程，我们使用了一个四级自上而下的框架来 (1) 界定需要评估的问题，(2) 将其转化为建模概念，(3) 推导出数学方程并用必要的数据填充它们计算特征因子，以及 (4) 使生命周期影响评估 (LCIA) 模型和生命周期清单 (LCI) 模型中的系统边界和假设保持一致。我们从使用资源问题的以下定义开始：由于妥协行动的最终结果，在很长一段时间或短期内，主要和/或次要元素在全球范围内的可访问性下降。系统模型区分了环境和技术领域中可访问和不可访问的库存。人类行为可以通过环境消散、技术圈休眠和使用中的占领或通过探索来损害可获取的存量。作为影响评估的基础，我们提出了两个参数：作为妥协行动的净结果的可获取种群的全球变化和可获取种群的全球数量。我们为元素的使用提出了三个影响类别：环境消散、技术圈休眠和使用中的职业，具有两个不同时间范围的相关特征方程。最后，在一个简单的说明性环境耗散案例研究中导出并应用了初步特征因子。由于数据限制，目前只能详细阐述很长一段时间内“对环境的耗散”的特征因素。案例研究表明，影响分数的计算可能会因 LCI 数据不足而受到阻碍。大多数目前可用的 LCI 数据库在登记评估对元素可访问性的影响所需的流量方面还远未完成。在应用该框架时，会做出各种可能做出不同选择的选择。