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Research article - Peer-reviewed, 2015

Time-Dynamic Effects on the Global Temperature When Harvesting Logging Residues for Bioenergy

Hammar, Torun; Ortiz, Carina; Stendahl, Johan; Ahlgren, Serina; Hansson, Per-Anders

Abstract

The climate mitigation potential of using logging residues (tree tops and branches) for bioenergy has been debated. In this study, a time-dependent life cycle assessment (LCA) was performed using a single-stand perspective. Three forest stands located in different Swedish climate zones were studied in order to assess the global temperature change when using logging residues for producing district heating. These systems were compared with two fossil reference systems in which the logging residues were assumed to remain in the forest to decompose over time, while coal or natural gas was used for energy. The results showed that replacing coal with logging residues gave a direct climate benefit from a single-stand perspective, while replacing natural gas gave a delayed climate benefit of around 8-12 years depending on climate zone. A sensitivity analysis showed that the time was strongly dependent on the assumptions for extraction and combustion of natural gas. The LCA showed that from a single-stand perspective, harvesting logging residues for bioenergy in the south of Sweden would give the highest temperature change mitigation potential per energy unit. However, the differences between the three climate zones studied per energy unit were relatively small. On a hectare basis, the southern forest stand would generate more biomass compared to the central and northern locations, which thereby could replace more fossil fuel and give larger climate benefits.

Keywords

Life cycle assessment; Soil organic carbon; Global warming; Boreal forest; Biogenic carbon; Greenhouse gas emissions

Published in

BioEnergy Research
2015, volume: 8, number: 4, pages: 1912-1924
Publisher: SPRINGER

Authors' information

Hammar, Torun
Swedish University of Agricultural Sciences, Department of Energy and Technology
Ortiz, Carina
Swedish University of Agricultural Sciences, Department of Soil and Environment
Swedish University of Agricultural Sciences, Department of Soil and Environment
Swedish University of Agricultural Sciences, Department of Energy and Technology
Swedish University of Agricultural Sciences, Department of Energy and Technology

Sustainable Development Goals

SDG7 Affordable and clean energy
SDG13 Climate action

UKÄ Subject classification

Energy Systems
Forest Science
Climate Research

Publication Identifiers

DOI: https://doi.org/10.1007/s12155-015-9649-3

URI (permanent link to this page)

https://res.slu.se/id/publ/69066