Analyzing land-based climate mitigation measures requires the joint examination of the effects of multiple forcing agents. Non-CO₂ forcing agents are often converted into “physical” CO₂ equivalents, i.e., expressed in terms of how much CO₂ would be required to inflict the same climate forcing as one unit of the agent. Similar conversions can also be based on equal social cost. Social-cost-based CO₂ equivalents are ideal for economic applications, as they retain the correct social cost ratio between forcing agents. We present two kinds of social-cost-based CO₂ equivalents for albedo-induced (or any other transient) forcing. The emission equivalent expresses transient forcing as equivalent CO₂ emissions (tCO₂yr⁻¹). The stock equivalent expresses it as an equivalent reduction in the terrestrial carbon stock (tCO₂). We compare physical and social-cost-based CO₂ equivalents, showing that social-cost-based the emission equivalent is a generalization of its physical counterpart, whereas social-cost-based stock equivalent is not. Nevertheless, the two stock equivalents are structurally similar and of roughly the same magnitude. We discuss how the equivalents can be applied in economic analysis, provide numerical multiplier values for converting transient forcing into emission and stock equivalents, and assess the extent to which physical CO₂ equivalents distort the social valuation of transient forcing.

分析陆基气候减缓措施需要联合检查多种强迫因素的影响。非CO ₂强迫因子通常转化为“物理” CO ₂当量，即表示为造成与一个因子单位相同的气候强迫所需的CO _{2 量}。类似的转换也可以基于相等的社会成本。基于社会成本的CO ₂当量是经济应用的理想选择，因为它们在强迫因素之间保留了正确的社会成本比率。我们提出了两种基于社会成本的 CO ₂当量，用于反照率诱导（或任何其他瞬态）强迫。排放当量将瞬态强迫表示为当量 CO ₂排放 ( tCO ₂ yr ^-1 )。库当量将其表示为陆地碳库 ( tCO ₂ )的当量减少量。我们比较基于物理成本和社会成本的 CO ₂等量，表明基于社会成本的排放当量是其物理对应物的推广，而基于社会成本的存量当量则不是。尽管如此，这两个股票等价物在结构上相似且数量级大致相同。我们讨论了如何在经济分析中应用当量，提供将瞬态强迫转换为排放和存量当量的数值乘数值，并评估物理 CO ₂等量扭曲瞬态强迫的社会估值的程度。