Are Land-Use Change Emissions in Southeast Asia Decreasing or Increasing?
(2022) In Global Biogeochemical Cycles 36(1).- Abstract
Southeast Asia is a region known for active land-use changes (LUC) over the past 60 years; yet, how trends in net CO2 uptake and release resulting from LUC activities (net LUC flux) have changed through past decades remains uncertain. The level of uncertainty in net LUC flux from process-based models is so high that it cannot be concluded that newer estimates are necessarily more reliable than older ones. Here, we examined net LUC flux estimates of Southeast Asia for the 1980s−2010s from older and newer sets of Dynamic Global Vegetation Model simulations (TRENDY v2 and v7, respectively), and forcing data used for running those simulations, along with two book-keeping estimates (H&N and BLUE). These estimates yielded two... (More)
Southeast Asia is a region known for active land-use changes (LUC) over the past 60 years; yet, how trends in net CO2 uptake and release resulting from LUC activities (net LUC flux) have changed through past decades remains uncertain. The level of uncertainty in net LUC flux from process-based models is so high that it cannot be concluded that newer estimates are necessarily more reliable than older ones. Here, we examined net LUC flux estimates of Southeast Asia for the 1980s−2010s from older and newer sets of Dynamic Global Vegetation Model simulations (TRENDY v2 and v7, respectively), and forcing data used for running those simulations, along with two book-keeping estimates (H&N and BLUE). These estimates yielded two contrasting historical LUC transitions, such that TRENDY v2 and H&N showed a transition from increased emissions from the 1980s to 1990s to declining emissions in the 2000s, while TRENDY v7 and BLUE showed the opposite transition. We found that these contrasting transitions originated in the update of LUC forcing data, which reduced the loss of forest area during the 1990s. Further evaluation of remote sensing studies, atmospheric inversions, and the history of forestry and environmental policies in Southeast Asia supported the occurrence of peak emissions in the 1990s and declining thereafter. However, whether LUC emissions continue to decline in Southeast Asia remains uncertain as key processes in recent years, such as conversion of peat forest to oil-palm plantation, are yet to be represented in the forcing data, suggesting a need for further revision.
(Less)
- author
- organization
- publishing date
- 2022-01-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- atmospheric inversions, book-keeping models, Dynamic Global Vegetation Models, forest area, land-use changes, Southeast Asia
- in
- Global Biogeochemical Cycles
- volume
- 36
- issue
- 1
- article number
- e2020GB006909
- publisher
- American Geophysical Union (AGU)
- external identifiers
-
- scopus:85123680081
- ISSN
- 0886-6236
- DOI
- 10.1029/2020GB006909
- language
- English
- LU publication?
- yes
- id
- d6f43109-82ab-4d6e-8aa0-0a0512278b7d
- date added to LUP
- 2022-02-21 12:27:14
- date last changed
- 2023-05-10 11:07:16
@article{d6f43109-82ab-4d6e-8aa0-0a0512278b7d,
abstract = {{<p>Southeast Asia is a region known for active land-use changes (LUC) over the past 60 years; yet, how trends in net CO<sub>2</sub> uptake and release resulting from LUC activities (net LUC flux) have changed through past decades remains uncertain. The level of uncertainty in net LUC flux from process-based models is so high that it cannot be concluded that newer estimates are necessarily more reliable than older ones. Here, we examined net LUC flux estimates of Southeast Asia for the 1980s−2010s from older and newer sets of Dynamic Global Vegetation Model simulations (TRENDY v2 and v7, respectively), and forcing data used for running those simulations, along with two book-keeping estimates (H&N and BLUE). These estimates yielded two contrasting historical LUC transitions, such that TRENDY v2 and H&N showed a transition from increased emissions from the 1980s to 1990s to declining emissions in the 2000s, while TRENDY v7 and BLUE showed the opposite transition. We found that these contrasting transitions originated in the update of LUC forcing data, which reduced the loss of forest area during the 1990s. Further evaluation of remote sensing studies, atmospheric inversions, and the history of forestry and environmental policies in Southeast Asia supported the occurrence of peak emissions in the 1990s and declining thereafter. However, whether LUC emissions continue to decline in Southeast Asia remains uncertain as key processes in recent years, such as conversion of peat forest to oil-palm plantation, are yet to be represented in the forcing data, suggesting a need for further revision.</p>}},
author = {{Kondo, Masayuki and Sitch, Stephen and Ciais, Philippe and Achard, Frédéric and Kato, Etsushi and Pongratz, Julia and Houghton, Richard A. and Canadell, Josep G. and Patra, Prabir K. and Friedlingstein, Pierre and Li, Wei and Anthoni, Peter and Arneth, Almut and Chevallier, Frédéric and Ganzenmüller, Raphael and Harper, Anna and Jain, Atul K. and Koven, Charles and Lienert, Sebastian and Lombardozzi, Danica and Maki, Takashi and Nabel, Julia E.M.S. and Nakamura, Takashi and Niwa, Yosuke and Peylin, Philippe and Poulter, Benjamin and Pugh, Thomas A.M. and Rödenbeck, Christian and Saeki, Tazu and Stocker, Benjamin and Viovy, Nicolas and Wiltshire, Andy and Zaehle, Sönke}},
issn = {{0886-6236}},
keywords = {{atmospheric inversions; book-keeping models; Dynamic Global Vegetation Models; forest area; land-use changes; Southeast Asia}},
language = {{eng}},
month = {{01}},
number = {{1}},
publisher = {{American Geophysical Union (AGU)}},
series = {{Global Biogeochemical Cycles}},
title = {{Are Land-Use Change Emissions in Southeast Asia Decreasing or Increasing?}},
url = {{http://dx.doi.org/10.1029/2020GB006909}},
doi = {{10.1029/2020GB006909}},
volume = {{36}},
year = {{2022}},
}