Effects of anthropogenic land cover change on the carbon cycle of the last millennium
Transient simulations are performed over the entire last millennium with a general circulation model that couples the atmosphere, ocean, and the land surface with a closed carbon cycle. This setup applies a high-detail reconstruction of anthropogenic land cover change (ALCC) as the only forcing to t...
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ftpubman:oai:pure.mpg.de:item_993888 2023-08-27T04:10:00+02:00 Effects of anthropogenic land cover change on the carbon cycle of the last millennium Pongratz, J. Reick, C. Raddatz, T. Claussen, M. 2009-10 application/pdf http://hdl.handle.net/11858/00-001M-0000-0011-F788-D http://hdl.handle.net/21.11116/0000-000B-3059-B eng eng info:eu-repo/semantics/altIdentifier/doi/10.1029/2009GB003488 http://hdl.handle.net/11858/00-001M-0000-0011-F788-D http://hdl.handle.net/21.11116/0000-000B-3059-B info:eu-repo/semantics/openAccess Global Biogeochemical Cycles info:eu-repo/semantics/article 2009 ftpubman https://doi.org/10.1029/2009GB003488 2023-08-02T01:23:14Z Transient simulations are performed over the entire last millennium with a general circulation model that couples the atmosphere, ocean, and the land surface with a closed carbon cycle. This setup applies a high-detail reconstruction of anthropogenic land cover change (ALCC) as the only forcing to the climate system with two goals: (1) to isolate the effects of ALCC on the carbon cycle and the climate independently of any other natural and anthropogenic disturbance and (2) to assess the importance of preindustrial human activities. With ALCC as only forcing, the terrestrial biosphere experiences a net loss of 96 Gt C over the last millennium, leading to an increase of atmospheric CO2 by 20 ppm. The biosphere-atmosphere coupling thereby leads to a restoration of 37% and 48% of the primary emissions over the industrial (A. D. 1850-2000) and the preindustrial period (A.D. 800-1850), respectively. Because of the stronger coupling flux over the preindustrial period, only 21% of the 53 Gt C preindustrial emissions remain airborne. Despite the low airborne fraction, atmospheric CO2 rises above natural variability by late medieval times. This suggests that human influence on CO2 began prior to industrialization. Global mean temperatures, however, are not significantly altered until the strong population growth in the industrial period. Furthermore, we investigate the effects of historic events such as epidemics and warfare on the carbon budget. We find that only long-lasting events such as the Mongol invasion lead to carbon sequestration. The reason for this limited carbon sequestration is indirect emissions from past ALCC that compensate carbon uptake in regrowing vegetation for several decades. Drops in ice core CO2 are thus unlikely to be attributable to human action. Our results indicate that climate-carbon cycle studies for present and future centuries, which usually start from an equilibrium state around 1850, start from a significantly disturbed state of the carbon cycle. Article in Journal/Newspaper ice core Max Planck Society: MPG.PuRe Global Biogeochemical Cycles 23 4 n/a n/a |
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Open Polar |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
Transient simulations are performed over the entire last millennium with a general circulation model that couples the atmosphere, ocean, and the land surface with a closed carbon cycle. This setup applies a high-detail reconstruction of anthropogenic land cover change (ALCC) as the only forcing to the climate system with two goals: (1) to isolate the effects of ALCC on the carbon cycle and the climate independently of any other natural and anthropogenic disturbance and (2) to assess the importance of preindustrial human activities. With ALCC as only forcing, the terrestrial biosphere experiences a net loss of 96 Gt C over the last millennium, leading to an increase of atmospheric CO2 by 20 ppm. The biosphere-atmosphere coupling thereby leads to a restoration of 37% and 48% of the primary emissions over the industrial (A. D. 1850-2000) and the preindustrial period (A.D. 800-1850), respectively. Because of the stronger coupling flux over the preindustrial period, only 21% of the 53 Gt C preindustrial emissions remain airborne. Despite the low airborne fraction, atmospheric CO2 rises above natural variability by late medieval times. This suggests that human influence on CO2 began prior to industrialization. Global mean temperatures, however, are not significantly altered until the strong population growth in the industrial period. Furthermore, we investigate the effects of historic events such as epidemics and warfare on the carbon budget. We find that only long-lasting events such as the Mongol invasion lead to carbon sequestration. The reason for this limited carbon sequestration is indirect emissions from past ALCC that compensate carbon uptake in regrowing vegetation for several decades. Drops in ice core CO2 are thus unlikely to be attributable to human action. Our results indicate that climate-carbon cycle studies for present and future centuries, which usually start from an equilibrium state around 1850, start from a significantly disturbed state of the carbon cycle. |
format |
Article in Journal/Newspaper |
author |
Pongratz, J. Reick, C. Raddatz, T. Claussen, M. |
spellingShingle |
Pongratz, J. Reick, C. Raddatz, T. Claussen, M. Effects of anthropogenic land cover change on the carbon cycle of the last millennium |
author_facet |
Pongratz, J. Reick, C. Raddatz, T. Claussen, M. |
author_sort |
Pongratz, J. |
title |
Effects of anthropogenic land cover change on the carbon cycle of the last millennium |
title_short |
Effects of anthropogenic land cover change on the carbon cycle of the last millennium |
title_full |
Effects of anthropogenic land cover change on the carbon cycle of the last millennium |
title_fullStr |
Effects of anthropogenic land cover change on the carbon cycle of the last millennium |
title_full_unstemmed |
Effects of anthropogenic land cover change on the carbon cycle of the last millennium |
title_sort |
effects of anthropogenic land cover change on the carbon cycle of the last millennium |
publishDate |
2009 |
url |
http://hdl.handle.net/11858/00-001M-0000-0011-F788-D http://hdl.handle.net/21.11116/0000-000B-3059-B |
genre |
ice core |
genre_facet |
ice core |
op_source |
Global Biogeochemical Cycles |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/2009GB003488 http://hdl.handle.net/11858/00-001M-0000-0011-F788-D http://hdl.handle.net/21.11116/0000-000B-3059-B |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2009GB003488 |
container_title |
Global Biogeochemical Cycles |
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23 |
container_issue |
4 |
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n/a |
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1775351710616649728 |