Towards a non-ambiguous view of the amortization period for quantifying direct land-use change in LCAShow others and affiliations
2022 (English)In: The International Journal of Life Cycle Assessment, ISSN 0948-3349, E-ISSN 1614-7502, Vol. 27, no 12, p. 1299-1315Article in journal (Refereed) Published
Abstract [en]
Purpose To clarify the concept of the amortization period (20-year factor) associated with direct land-use change (dLUC) accounting, discuss its main inconsistencies, and propose improvements. The current practice is to divide (amortize) the estimated emissions associated with dLUC that has occurred over the last 20 years by another 20 years. Both periods are referred ambiguously as "amortization period." Issues arise when considering them as a single temporal aspect (TA) that cannot fully represent the complexity of diverse research and policy contexts. Methods First, a systematic review was conducted to understand the 20-year amortization history and concepts and discuss its inconsistencies. Based on the review results, we propose the adoption of two distinct TAs, decomposed from the "amortization period." Then, we performed a sensitivity analysis by estimating carbon emissions due to dLUC in six land uses in Brazil: soybean, maize, sugarcane, pasture, planted forest, and mango. Results and discussion The literature review shows that several strategies have emerged to reduce or avoid adopting the amortization period. However, most of these proposals are based on complex approaches focusing on alternatives associated with the life cycle impact assessment stage. We found that the commonly adopted amortization period has an ambiguous nature that could be explored at the life cycle inventory analysis stage. Thus, we argue that there are two distinct TAs linked to amortization in dLUC: (i) the inventory period adopted to account for land-use changes; and (ii) the period over which carbon emissions are annualized. These temporal aspects were named here the "LUC-inventory period" (IP) and the "LUC-amortization period" (AP), for clarification purposes. The sensitivity analysis showed that different values of IP and AP drastically change the emissions results due to dLUC in Brazil for different crops and land uses. Conclusion We advocate that the "amortization period" should be decomposed into two TAs: "LUC-inventory period" and the "LUC-amortization period." They affect how the carbon debt incurred by expanding agricultural land is accounted for and amortized over a given period-of-time. Therefore, to ensure regulatory compliance, we argued that these proposed TAs should be explicitly defined, based on three possibilities, depending on the goal and context of LCA studies, such as (i) fixed values set in standards and norms; (ii) IPCC's 20-year defaults; and (iii) customized IP and AP values based on the study's specificities.
Place, publisher, year, edition, pages
Springer Nature , 2022. Vol. 27, no 12, p. 1299-1315
Keywords [en]
Temporal aspects, Land transformation, LUC, Temporal dependence, Carbon footprint
National Category
Environmental Sciences
Identifiers
URN: urn:nbn:se:kth:diva-321913DOI: 10.1007/s11367-022-02103-3ISI: 000879719800002Scopus ID: 2-s2.0-85141387035OAI: oai:DiVA.org:kth-321913DiVA, id: diva2:1716629
Note
QC 20221206
2022-12-062022-12-062022-12-06Bibliographically approved