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The time aspect of bioenergy - Climate impacts of solid biofuels due to biogenic carbon dynamics

Zetterberg, Lars and Chen, Deliang (2014) In Global Change Biology Bioenergy Epub ahead of print.
Abstract
The climate impacts from bioenergy involve an important time aspect. Using forest residues for energy may result in high initial emissions, but net emissions are reduced over time since, if the residues were left on the ground, they would decompose and release CO2 to the atmosphere. This article investigates the climate impacts from bioenergy with special focus on the time aspects. More specifically, we analyze the climate impacts of forest residues and stumps where combustion related emissions are compensated by avoided emissions from leaving them on the ground to decompose. These biofuels are compared with fossil gas and coal. Net emissions are defined as emissions from utilizing the fuel minus emissions from a reference case of no... (More)
The climate impacts from bioenergy involve an important time aspect. Using forest residues for energy may result in high initial emissions, but net emissions are reduced over time since, if the residues were left on the ground, they would decompose and release CO2 to the atmosphere. This article investigates the climate impacts from bioenergy with special focus on the time aspects. More specifically, we analyze the climate impacts of forest residues and stumps where combustion related emissions are compensated by avoided emissions from leaving them on the ground to decompose. These biofuels are compared with fossil gas and coal. Net emissions are defined as emissions from utilizing the fuel minus emissions from a reference case of no utilization. Climate impacts are estimated using the measures radiative forcing and global average surface temperature. We find that the climate impacts from using forest residues and stumps depend on the decomposition rates and the time perspective over which the analysis is done. Over a 100 year perspective, branches and tops have lower climate impacts than stumps which in turn have lower impacts than fossil gas and coal. Over a 20 year time perspective, branches and tops have lower climate impacts than all other fuels but the relative difference is smaller. However, stumps have slightly higher climate impacts over 20 years than fossil gas but lower impacts than coal. Regarding metrics for climate impacts, over shorter time scales, approximately 30 years or less, radiative forcing overestimates the climate impacts compared with impacts expressed by global surface temperature change, which is due to the inertia of the climate system. We also find that establishing willow on earlier crop land may reduce atmospheric CO2, provided new land is available. However, these results are inconclusive since we haven't considered the effects of producing the agricultural crops elsewhere. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
bioenergy, climate impacts, forest residues, global average surface temperature, radiative forcing, stumps, time aspects, willow
in
Global Change Biology Bioenergy
volume
Epub ahead of print
publisher
John Wiley & Sons
external identifiers
  • scopus:84931028660
ISSN
1757-1693
DOI
10.1111/gcbb.12174
project
MERGE
language
English
LU publication?
no
id
beb6e669-ddcc-4110-ac7a-31eb1a4c6456 (old id 7515635)
date added to LUP
2015-07-08 14:39:05
date last changed
2017-08-20 04:38:43
@article{beb6e669-ddcc-4110-ac7a-31eb1a4c6456,
  abstract     = {The climate impacts from bioenergy involve an important time aspect. Using forest residues for energy may result in high initial emissions, but net emissions are reduced over time since, if the residues were left on the ground, they would decompose and release CO2 to the atmosphere. This article investigates the climate impacts from bioenergy with special focus on the time aspects. More specifically, we analyze the climate impacts of forest residues and stumps where combustion related emissions are compensated by avoided emissions from leaving them on the ground to decompose. These biofuels are compared with fossil gas and coal. Net emissions are defined as emissions from utilizing the fuel minus emissions from a reference case of no utilization. Climate impacts are estimated using the measures radiative forcing and global average surface temperature. We find that the climate impacts from using forest residues and stumps depend on the decomposition rates and the time perspective over which the analysis is done. Over a 100 year perspective, branches and tops have lower climate impacts than stumps which in turn have lower impacts than fossil gas and coal. Over a 20 year time perspective, branches and tops have lower climate impacts than all other fuels but the relative difference is smaller. However, stumps have slightly higher climate impacts over 20 years than fossil gas but lower impacts than coal. Regarding metrics for climate impacts, over shorter time scales, approximately 30 years or less, radiative forcing overestimates the climate impacts compared with impacts expressed by global surface temperature change, which is due to the inertia of the climate system. We also find that establishing willow on earlier crop land may reduce atmospheric CO2, provided new land is available. However, these results are inconclusive since we haven't considered the effects of producing the agricultural crops elsewhere.},
  author       = {Zetterberg, Lars and Chen, Deliang},
  issn         = {1757-1693},
  keyword      = {bioenergy,climate impacts,forest residues,global average surface temperature,radiative forcing,stumps,time aspects,willow},
  language     = {eng},
  publisher    = {John Wiley & Sons},
  series       = {Global Change Biology Bioenergy},
  title        = {The time aspect of bioenergy - Climate impacts of solid biofuels due to biogenic carbon dynamics},
  url          = {http://dx.doi.org/10.1111/gcbb.12174},
  volume       = {Epub ahead of print},
  year         = {2014},
}