N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions
Carbon–nitrogen (C–N) interactions regulate N availability for plant growth and for emissions of nitrous oxide (N2O) and the uptake of carbon dioxide. Future projections of these terrestrial greenhouse gas fluxes are strikingly divergent, leading to major uncertainties in projected global warming. H...
Main Authors: | , , , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus
2020
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11850/429152 https://doi.org/10.3929/ethz-b-000429152 |
id |
ftethz:oai:www.research-collection.ethz.ch:20.500.11850/429152 |
---|---|
record_format |
openpolar |
spelling |
ftethz:oai:www.research-collection.ethz.ch:20.500.11850/429152 2023-05-15T16:39:24+02:00 N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions Joos, Fortunat Spahni, Renato Stocker, Benjamin Lienert, Sebastian Müller, Jurek Fischer, Hubertus Schmitt, Jochen Prentice, I. Colin Otto-Bliesner, Bette Liu, Zhengyu 2020 application/application/pdf https://hdl.handle.net/20.500.11850/429152 https://doi.org/10.3929/ethz-b-000429152 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-17-3511-2020 info:eu-repo/semantics/altIdentifier/wos/000548520500003 http://hdl.handle.net/20.500.11850/429152 doi:10.3929/ethz-b-000429152 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY Biogeosciences, 17 (13) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2020 ftethz https://doi.org/20.500.11850/429152 https://doi.org/10.3929/ethz-b-000429152 https://doi.org/10.5194/bg-17-3511-2020 2023-02-13T00:52:29Z Carbon–nitrogen (C–N) interactions regulate N availability for plant growth and for emissions of nitrous oxide (N2O) and the uptake of carbon dioxide. Future projections of these terrestrial greenhouse gas fluxes are strikingly divergent, leading to major uncertainties in projected global warming. Here we analyse the large increase in terrestrial N2O emissions over the past 21 000 years as reconstructed from ice-core isotopic data and presented in part 1 of this study. Remarkably, the increase occurred in two steps, each realized over decades and within a maximum of 2 centuries, at the onsets of the major deglacial Northern Hemisphere warming events. The data suggest a highly dynamic and responsive global N cycle. The increase may be explained by an increase in the flux of reactive N entering and leaving ecosystems or by an increase in N2O yield per unit N converted. We applied the LPX-Bern dynamic global vegetation model in deglacial simulations forced with Earth system model climate data to investigate N2O emission patterns, mechanisms, and C–N coupling. The N2O emission changes are mainly attributed to changes in temperature and precipitation and the loss of land due to sea-level rise. LPX-Bern simulates a deglacial increase in N2O emissions but underestimates the reconstructed increase by 47 %. Assuming time-independent N sources in the model to mimic progressive N limitation of plant growth results in a decrease in N2O emissions in contrast to the reconstruction. Our results appear consistent with suggestions of (a) biological controls on ecosystem N acquisition and (b) flexibility in the coupling of the C and N cycles during periods of rapid environmental change. A dominant uncertainty in the explanation of the reconstructed N2O emissions is the poorly known N2O yield per N lost through gaseous pathways and its sensitivity to soil conditions. The deglacial N2O record provides a constraint for future studies. ISSN:1726-4170 ISSN:1726-4170 Article in Journal/Newspaper ice core ETH Zürich Research Collection |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
Carbon–nitrogen (C–N) interactions regulate N availability for plant growth and for emissions of nitrous oxide (N2O) and the uptake of carbon dioxide. Future projections of these terrestrial greenhouse gas fluxes are strikingly divergent, leading to major uncertainties in projected global warming. Here we analyse the large increase in terrestrial N2O emissions over the past 21 000 years as reconstructed from ice-core isotopic data and presented in part 1 of this study. Remarkably, the increase occurred in two steps, each realized over decades and within a maximum of 2 centuries, at the onsets of the major deglacial Northern Hemisphere warming events. The data suggest a highly dynamic and responsive global N cycle. The increase may be explained by an increase in the flux of reactive N entering and leaving ecosystems or by an increase in N2O yield per unit N converted. We applied the LPX-Bern dynamic global vegetation model in deglacial simulations forced with Earth system model climate data to investigate N2O emission patterns, mechanisms, and C–N coupling. The N2O emission changes are mainly attributed to changes in temperature and precipitation and the loss of land due to sea-level rise. LPX-Bern simulates a deglacial increase in N2O emissions but underestimates the reconstructed increase by 47 %. Assuming time-independent N sources in the model to mimic progressive N limitation of plant growth results in a decrease in N2O emissions in contrast to the reconstruction. Our results appear consistent with suggestions of (a) biological controls on ecosystem N acquisition and (b) flexibility in the coupling of the C and N cycles during periods of rapid environmental change. A dominant uncertainty in the explanation of the reconstructed N2O emissions is the poorly known N2O yield per N lost through gaseous pathways and its sensitivity to soil conditions. The deglacial N2O record provides a constraint for future studies. ISSN:1726-4170 ISSN:1726-4170 |
format |
Article in Journal/Newspaper |
author |
Joos, Fortunat Spahni, Renato Stocker, Benjamin Lienert, Sebastian Müller, Jurek Fischer, Hubertus Schmitt, Jochen Prentice, I. Colin Otto-Bliesner, Bette Liu, Zhengyu |
spellingShingle |
Joos, Fortunat Spahni, Renato Stocker, Benjamin Lienert, Sebastian Müller, Jurek Fischer, Hubertus Schmitt, Jochen Prentice, I. Colin Otto-Bliesner, Bette Liu, Zhengyu N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions |
author_facet |
Joos, Fortunat Spahni, Renato Stocker, Benjamin Lienert, Sebastian Müller, Jurek Fischer, Hubertus Schmitt, Jochen Prentice, I. Colin Otto-Bliesner, Bette Liu, Zhengyu |
author_sort |
Joos, Fortunat |
title |
N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions |
title_short |
N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions |
title_full |
N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions |
title_fullStr |
N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions |
title_full_unstemmed |
N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions |
title_sort |
n2o changes from the last glacial maximum to the preindustrial – part 2: terrestrial n2o emissions and carbon–nitrogen cycle interactions |
publisher |
Copernicus |
publishDate |
2020 |
url |
https://hdl.handle.net/20.500.11850/429152 https://doi.org/10.3929/ethz-b-000429152 |
genre |
ice core |
genre_facet |
ice core |
op_source |
Biogeosciences, 17 (13) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-17-3511-2020 info:eu-repo/semantics/altIdentifier/wos/000548520500003 http://hdl.handle.net/20.500.11850/429152 doi:10.3929/ethz-b-000429152 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/429152 https://doi.org/10.3929/ethz-b-000429152 https://doi.org/10.5194/bg-17-3511-2020 |
_version_ |
1766029742221295616 |