生命周期评估（LCA）和温室气（GHG）库存是两个关键的测量工具，用于跟踪组织的环境影响。

一个比另一个更有效吗？答案通常取决于情况和组织的目标。有时，答案是“两者”。

WSPUSA partners with organizations aiming to be Future Ready®, helping them understand the differences and similarities between LCA and GHG inventory methods and data, and identifying whether it is beneficial to use each methodology separately or together to gain the most value and guide sustainability strategy.

什么是LCA和GHG库存？

LCA是一种工具used to quantify the environmental impacts from the raw materials, production, transportation, use and end of life of a product or service.

LCAs are often conducted to understand the total environmental impacts of a particular product or service and the drivers of those impacts. The goal is usually to reduce the environmental impacts such as GHG emissions, energy, air quality, water consumption and water quality indicators of those products and services, and to communicate to clients and customers about these impacts and how they compare to alternatives.

另一方面，组织的GHG库存是对组织价值链中组织的所有温室气体排放的总结。GHG库存通常是为了支持公司范围内的报告，为整个组织设定温室气体排放目标，并跟踪达到目标目标的进度。这是识别和理解组织内温室气体排放最大来源的绝佳方法。

温室气体排放通常分为三个范围：

• Scope 1 – Direct (fossil fuel combustion in vehicles, generation of heat and power
• Scope 2 – Indirect (purchased electricity)
• 范围3 - 价值链的排放分为15个类别（例如上游购买商品，下游使用商品，员工通勤和商务旅行）。

执行LCA的见解

组织可以进行LCA的原因有几个。

可能需要推动内部创新，以减少产品和服务的环境影响。188bet上不了也许需要组织满足外部政策要求或客户要求。也许需要证实有关产品或服务的单数或比较可持续性的外部营销主张。金博宝怎么注册或者可能是重新评估产品环境影响的时候，以使其转向更可持续的设计。此外，LCA通常会提供环境影响，而不仅仅是温室气体排放，这些排放量提供了对产品或服务的整体环境影响的见解。

Extracting the most value from an LCA means engaging partners across the organization from design to marketing to drive innovation and communicate results strategically.

通常，LCA的结果在年度可持续性报告中得到强调，并且可以帮助跟踪随着时间的推移而降低温室气金博宝怎么注册体排放目标的进度，尤其是与购买的商品和服务，使用产品和其他范围3类别有关。188bet上不了一种称为环境产品声明（EPD）的LCA类型是基于所有属于该类别的产品的产品类别规则进行LCA进行通信的精确格式。

EPDs are valuable standardized methods of reporting LCA results to customers and serve as useful marketing tools. They also inform other LCAs and GHG inventories.

WSPcompleted anISO-conformant comparative LCA for Perfect Day, a manufacturer of animal-free dairy protein. The analysis compared Perfect Day’s non-animal whey protein and the total protein in bovine milk to demonstrate that Perfect Day’s whey substantially reduces GHG emissions, energy and water consumption.

Perfect Day can now use these results to support its communications about the enhanced environmental attributes of its whey with confidence because the study was critically reviewed by a panel of three independent experts and verified to be in accordance with ISO-standards 14040 and 14044. This is considered best practice to support environmental claims.

现在，如果食品制造商使用完美的乳清来代替其他成分，LCA的结果可以告知其自己的LCA和范围3 GHG库存，并计算出温室气体排放和其他环境影响的潜在减少。

Furthermore, if Perfect Day decided to conduct its own GHG inventory to better understand the GHG emissions footprint of the organization and identify additional opportunities to extend its environmental impact, it could use the results of the LCA to inform several Scope 3 categories.

Insights from Performing a GHG Inventory

组织以多种原因计算GHG库存。它们提供了有价值的业务信息，可用于制定减少温室气体排放的策略。温室气体库存还通过报告提高了组织的环境透明度，它们对于在随着时间的推移而实现温室气体排放量减少目标方面的设定和跟踪进展非常有用。

客户，投资者和其他利益相关者可能会要求将GHG清单的结果包括在标准报告中，并可以根据其满足温室气体减少目标的能力来评估组织。WSP计算了自己的温室气体库存，并帮助众多组织计算了温室气体库存，设定了减少目标，创建减少路线图并跟踪达到减少目标的进度。

与LCA相比，温室气体库存更适合整个组织的大规模分析。这并不是说LCA不能应用于组织，但是与使用GHG库存方法和数据相比，它可能需要更多的时间，并且需要更多的数据才能通过LCA完成此评估。

WSP与孩子们的地方合作, a specialty retailer of children’s apparel, as a professional services provider to develop a GHG inventory for the company’s climate disclosures. In this role, WSP’s Sustainability, Energy and Climate Change team calculated the company’s first water inventory and collected and analyzed GHG emissions data to identify areas where there were opportunities to reduce environmental impact.

The data was collected and used to calculate the annual reporting data concerning energy and water usage and GHG emissions, which was reported in The Children’s Place’s2020年环境，社会和治理报告。使用数据，零售商设定了其目标在2030年实现的气候和能源目标，其中包括范围1的范围1和范围2基于市场的GHG排放量的30％，以及30％的范围3温室气体排放量减少了30％来自购买的商品和产品运输。

对于某些范围3温室气体会计类别，支出数据通常用于计算排放。支出数据分配了每美元花费的温室气体排放强度，这适用于组织在每个范围3类别中花费的金额。这对于了解推动组织温室气体排放的最相关类别非常有用。

但是，在没有更多产品，服务和类别的数据的情况下，减少这些类别中的温室气体排放变得更加困难。越来越多地获得有关已发表LCA或EPD的产品类型的全能温室气体排放数据，并且使用此类数据可以提高温室气体库存的特异性，并突出显示比支出数据更可行的目标。

如果一个组织专门从事特定产品制造，那么特定于产品的LCA可以进一步提高温室气体库存的准确性，并突出供应链的特定部分，以减少GHG排放。

GHG方案有一个产品碳足迹标准，但这仅涵盖温室气体排放，并且没有其他环境影响，例如水和空气质量，用水，消费和稀缺，能源或其他可以包含在LCA中的类别。因此，作为一种量化方法，除生产，运输，运输，使用和生命终止的温室气体排放外，公司碳核算账目不能用于列举环境影响。

混合这两种方法

There is some confusion in the sustainability space between LCAs and GHG inventories. For example, neither method produces better or more accurate results than the other. The accuracy of either method depends on the accuracy of the input data.

但是，它们可以同时使用来支持组织的整体环境目标。

LCA可以使GHG库存的范围3数据输入更精确，并支持对GHG库存范围3的计算，并更深入地研究3类区域，包括1类（购买的商品和服务），第10类（处理产品的处理），188bet上不了类别4和9（上游和下游运输和分销），类别11（使用销售产品）或第12类（销售产品的生命终止处理）。

WSPis conducting both product LCAs and GHG inventories for many organizations and uses the results of product LCAs and EPDs to calculate more precise and actionable Scope 3 GHG emissions. The key is understanding which results can be used to inform the categories in Scope 3 GHG inventories.

最近出版的白皮书由Microsoft和WSP合着LCA Guidelines for Cloud Providers, explores the importance of understanding the life cycle of GHG emissions, energy, water and other environmental impacts of technology, from servers to full datacenters