Permafrost region greenhouse gas budgets suggest a weak CO2 sink and CH4 and N2O sources, but magnitudes differ between top-down and bottom-up methods

Hugelius, G., Ramage, J., Burke, E., Chatterjee, A., Smallman, T. L., Aalto, T., Bastos, A., Biasi, C., Canadell, J. G., Chandra, N., Chevallier, F., Ciais, P., Chang, J., Feng, L., Jones, M. W. ORCID: https://orcid.org/0000-0003-3480-7980, Kleinen, T., Kuhn, M., Lauerwald, R., Liu, J., López-Blanco, E., Luijkx, I. T., Marushchak, M. E., Natali, S. M., Niwa, Y., Olefeldt, D., Palmer, P. I., Patra, P. K., Peters, W., Potter, S., Poulter, B., Rogers, B. M., Riley, W. J., Saunois, M., Schuur, E. A. G., Thompson, R. L., Treat, C., Tsuruta, A., Turetsky, M. R., Virkkala, A.-M., Voigt, C., Watts, J., Zhu, Q. and Zheng, B. (2024) Permafrost region greenhouse gas budgets suggest a weak CO2 sink and CH4 and N2O sources, but magnitudes differ between top-down and bottom-up methods. Global Biogeochemical Cycles, 38 (10). ISSN 0886-6236

Preview

PDF (Global Biogeochemical Cycles - 2024 - Hugelius - Permafrost Region Greenhouse Gas Budgets Suggest a Weak CO2 Sink and CH4) - Published Version Available under License Creative Commons Attribution. Download (2MB) | Preview

Abstract

Large stocks of soil carbon (C) and nitrogen (N) in northern permafrost soils are vulnerable to remobilization under climate change. However, there are large uncertainties in present-day greenhouse gas (GHG) budgets. We compare bottom-up (data-driven upscaling and process-based models) and top-down (atmospheric inversion models) budgets of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) as well as lateral fluxes of C and N across the region over 2000–2020. Bottom-up approaches estimate higher land-to-atmosphere fluxes for all GHGs. Both bottom-up and top-down approaches show a sink of CO2 in natural ecosystems (bottom-up: −29 (−709, 455), top-down: −587 (−862, −312) Tg CO2-C yr−1) and sources of CH4 (bottom-up: 38 (22, 53), top-down: 15 (11, 18) Tg CH4-C yr−1) and N2O (bottom-up: 0.7 (0.1, 1.3), top-down: 0.09 (−0.19, 0.37) Tg N2O-N yr−1). The combined global warming potential of all three gases (GWP-100) cannot be distinguished from neutral. Over shorter timescales (GWP-20), the region is a net GHG source because CH4 dominates the total forcing. The net CO2 sink in Boreal forests and wetlands is largely offset by fires and inland water CO2 emissions as well as CH4 emissions from wetlands and inland waters, with a smaller contribution from N2O emissions. Priorities for future research include the representation of inland waters in process-based models and the compilation of process-model ensembles for CH4 and N2O. Discrepancies between bottom-up and top-down methods call for analyses of how prior flux ensembles impact inversion budgets, more and well-distributed in situ GHG measurements and improved resolution in upscaling techniques.

Item Type:	Article
Additional Information:	Data Availability Statement: Process-based model simulations were accessed from their archives, including the CMIP5 archive (https://esgf-node.llnl.gov/search/cmip5) and CMIP6 archive (https://esgf-node.llnl.gov/search/cmip6). We downloaded and extracted carbon stocks and fluxes from both the Permafrost Carbon Network (PCN) and Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) ensembles via the ORNL DAAC (Huntzinger et al., 2018; McGuire et al., 2022, respectively). Data from the Inter-Sectoral Impact Model Intercomparison Project phases 2 and 3 (ISIMIP2a and ISIMIP2b) is available from https://www.isimip.org. CARDAMOM data is available via https://doi.org/10.7488/ds/7505. All data sources for data-driven ecosystem upscaling are provided by Ramage et al. (2024). Monthly data for all models included in the top-down inversion ensembles are available via the Bolin Centre Database (Hugelius et al., 2024). The CARDAMOM-permafrost data set can be freely downloaded from https://doi.org/10.7488/ds/7505. Funding information: European Union's Horizon 2020 Research and Innovation Programme to the Nunataryuk. Grant Number: 773421; Swedish Research Council. Grant Number: 2022-04839; Swedish Academy of Science. Grant Number: FR-2021/0004; Atmosphere and Climate Competence Center. Grant Number: 337550; National Aeronautics and Space Administration. Grant Number: 80NM0018D0004; German Federal Ministry of Education and Research. Grant Number: 01LP1921A; Natural Environment Research Council. Grant Number: NE/R016518/1, NE/N018079/1
Uncontrolled Keywords:	sdg 13 - climate action,sdg 15 - life on land ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School:	Faculty of Science > School of Environmental Sciences University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups:	Faculty of Science > Research Groups > Climatic Research Unit University of East Anglia Schools > Faculty of Science > Tyndall Centre for Climate Change Research Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
Related URLs:	https://agupubs.onlinelibrary.wiley.com/...
Depositing User:	LivePure Connector
Date Deposited:	01 Nov 2024 09:30
Last Modified:	12 Nov 2024 14:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/97406
DOI:	10.1029/2023GB007969

Downloads

Actions (login required)

View Item