Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty
Estimating the impacts of climate change on the global carbon cycle relies on projections from Earth system models (ESMs). While ESMs currently project large warming in the high northern latitudes, the magnitude and sign of the future carbon balance of Arctic-Boreal ecosystems are highly uncertain....
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Online Access: | https://doi.org/10.1088/1748-9326/acb226 https://doaj.org/article/6d0aef84ba5c48d88e0cc647cff17675 |
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ftdoajarticles:oai:doaj.org/article:6d0aef84ba5c48d88e0cc647cff17675 2023-09-05T13:16:58+02:00 Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty Renato K Braghiere Joshua B Fisher Kimberley R Miner Charles E Miller John R Worden David S Schimel Christian Frankenberg 2023-01-01T00:00:00Z https://doi.org/10.1088/1748-9326/acb226 https://doaj.org/article/6d0aef84ba5c48d88e0cc647cff17675 EN eng IOP Publishing https://doi.org/10.1088/1748-9326/acb226 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/acb226 1748-9326 https://doaj.org/article/6d0aef84ba5c48d88e0cc647cff17675 Environmental Research Letters, Vol 18, Iss 2, p 025008 (2023) NASA ABoVE CMIP5 CMIP6 tipping point carbon cycle soil carbon Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 article 2023 ftdoajarticles https://doi.org/10.1088/1748-9326/acb226 2023-08-13T00:36:48Z Estimating the impacts of climate change on the global carbon cycle relies on projections from Earth system models (ESMs). While ESMs currently project large warming in the high northern latitudes, the magnitude and sign of the future carbon balance of Arctic-Boreal ecosystems are highly uncertain. The new generation of increased complexity ESMs in the Intergovernmental Panel on Climate Change Sixth Assessment Report (IPCC AR6) is intended to improve future climate projections. Here, we benchmark the Coupled Model Intercomparison Project (CMIP) 5 and 6 (8 CMIP5 members and 12 CMIP6 members) with the International Land Model Benchmarking (ILAMB) tool over the region of NASA’s Arctic-Boreal vulnerability experiment (ABoVE) in North America. We show that the projected average net biome production (NBP) in 2100 from CMIP6 is higher than that from CMIP5 in the ABoVE domain, despite the model spread being slightly narrower. Overall, CMIP6 shows better agreement with contemporary observed carbon cycle variables (photosynthesis, respiration, biomass) than CMIP5, except for soil carbon and turnover time. Although both CMIP ensemble members project the ABoVE domain will remain a carbon sink by the end of the 21st century, the sink strength in CMIP6 increases with CO _2 emissions. CMIP5 and CMIP6 ensembles indicate a tipping point defined here as a negative inflection point in the NBP curve by 2050–2080 independently of the shared socioeconomic pathway (SSP) for CMIP6 or representative concentration pathway (RCP) for CMIP5. The model ensembles therefore suggest that, if the carbon sink strength keeps declining throughout the 21st century, the Arctic-Boreal ecosystems in North America may become a carbon source over the next century. Article in Journal/Newspaper Arctic Climate change Directory of Open Access Journals: DOAJ Articles Arctic Environmental Research Letters 18 2 025008 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
NASA ABoVE CMIP5 CMIP6 tipping point carbon cycle soil carbon Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
spellingShingle |
NASA ABoVE CMIP5 CMIP6 tipping point carbon cycle soil carbon Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 Renato K Braghiere Joshua B Fisher Kimberley R Miner Charles E Miller John R Worden David S Schimel Christian Frankenberg Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty |
topic_facet |
NASA ABoVE CMIP5 CMIP6 tipping point carbon cycle soil carbon Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
description |
Estimating the impacts of climate change on the global carbon cycle relies on projections from Earth system models (ESMs). While ESMs currently project large warming in the high northern latitudes, the magnitude and sign of the future carbon balance of Arctic-Boreal ecosystems are highly uncertain. The new generation of increased complexity ESMs in the Intergovernmental Panel on Climate Change Sixth Assessment Report (IPCC AR6) is intended to improve future climate projections. Here, we benchmark the Coupled Model Intercomparison Project (CMIP) 5 and 6 (8 CMIP5 members and 12 CMIP6 members) with the International Land Model Benchmarking (ILAMB) tool over the region of NASA’s Arctic-Boreal vulnerability experiment (ABoVE) in North America. We show that the projected average net biome production (NBP) in 2100 from CMIP6 is higher than that from CMIP5 in the ABoVE domain, despite the model spread being slightly narrower. Overall, CMIP6 shows better agreement with contemporary observed carbon cycle variables (photosynthesis, respiration, biomass) than CMIP5, except for soil carbon and turnover time. Although both CMIP ensemble members project the ABoVE domain will remain a carbon sink by the end of the 21st century, the sink strength in CMIP6 increases with CO _2 emissions. CMIP5 and CMIP6 ensembles indicate a tipping point defined here as a negative inflection point in the NBP curve by 2050–2080 independently of the shared socioeconomic pathway (SSP) for CMIP6 or representative concentration pathway (RCP) for CMIP5. The model ensembles therefore suggest that, if the carbon sink strength keeps declining throughout the 21st century, the Arctic-Boreal ecosystems in North America may become a carbon source over the next century. |
format |
Article in Journal/Newspaper |
author |
Renato K Braghiere Joshua B Fisher Kimberley R Miner Charles E Miller John R Worden David S Schimel Christian Frankenberg |
author_facet |
Renato K Braghiere Joshua B Fisher Kimberley R Miner Charles E Miller John R Worden David S Schimel Christian Frankenberg |
author_sort |
Renato K Braghiere |
title |
Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty |
title_short |
Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty |
title_full |
Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty |
title_fullStr |
Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty |
title_full_unstemmed |
Tipping point in North American Arctic-Boreal carbon sink persists in new generation Earth system models despite reduced uncertainty |
title_sort |
tipping point in north american arctic-boreal carbon sink persists in new generation earth system models despite reduced uncertainty |
publisher |
IOP Publishing |
publishDate |
2023 |
url |
https://doi.org/10.1088/1748-9326/acb226 https://doaj.org/article/6d0aef84ba5c48d88e0cc647cff17675 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change |
genre_facet |
Arctic Climate change |
op_source |
Environmental Research Letters, Vol 18, Iss 2, p 025008 (2023) |
op_relation |
https://doi.org/10.1088/1748-9326/acb226 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/acb226 1748-9326 https://doaj.org/article/6d0aef84ba5c48d88e0cc647cff17675 |
op_doi |
https://doi.org/10.1088/1748-9326/acb226 |
container_title |
Environmental Research Letters |
container_volume |
18 |
container_issue |
2 |
container_start_page |
025008 |
_version_ |
1776198346834182144 |