Preprints
https://doi.org/10.5194/egusphere-2024-823
https://doi.org/10.5194/egusphere-2024-823
25 Mar 2024
 | 25 Mar 2024

Uncertainty in Amazon vegetation productivity in CMIP6 projections driven by surface energy fluxes

Matteo Mastropierro, Daniele Peano, and Davide Zanchettin

Abstract. The Amazon basin rainforest is a critical component of the climate system, currently representing 25 % of terrestrial carbon gains and storing 150 to 200 billion tonnes of carbon. If and by which extent the Amazon rainforest will remain a net carbon sink is an open scientific question, motivated by the unexplained diversity across Earth System Model (ESM) results. Specifically, divergent responses are observed in Amazon vegetation productivity projections, especially under sustained global warming scenarios. We explore this inter-model diversity in projected Amazon vegetation in CMIP6 historical and ssp585 scenario simulations with thirteen ESM by explicitly accounting for the relative contributions of changes in the El Niño-Southern Oscillation (ENSO) and local mean-state climate changes. Our results demonstrate the dominant role of local mean-state climatic changes in shaping the response of the Amazon carbon cycle for 7 out of 13 ESM, with only a minor role for changes in ENSO and its teleconnection despite the strong inter-model diversity in representing ENSO. While temperature and water availability influence displays a high inter-model agreement, the most critical local processes determining uncertainty and divergence across ESM responses within the Amazon basin are the surface energy balance components, in particular shortwave incoming radiation and latent heat fluxes. We identify the main sources of model specificities in land scheme parameterizations, especially the incorporation of Phosphorous limitation, which leads to a stronger reduction of vegetation productivity under strong warming scenarios. We therefore advocate for increased focus from modelling groups towards a more accurate and consistent representation of surface radiative and turbulent fluxes in the Amazon region. Additionally, we hypothesize that a uniform incorporation of Phosphorous limitation across all the ESM may contribute to minimize the uncertainties. This dual approach can lead to more robust estimates of vegetation productivity within the Amazon basin across different climate change scenarios.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
Share

Journal article(s) based on this preprint

01 Oct 2025
Drivers of and uncertainty in Amazon carbon sink long-term and interannual variability in CMIP6 models
Matteo Mastropierro, Daniele Peano, and Davide Zanchettin
Biogeosciences, 22, 5231–5246, https://doi.org/10.5194/bg-22-5231-2025,https://doi.org/10.5194/bg-22-5231-2025, 2025
Short summary
Matteo Mastropierro, Daniele Peano, and Davide Zanchettin

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-823', Anonymous Referee #1, 06 May 2024
  • RC2: 'Comment on egusphere-2024-823', Anonymous Referee #2, 27 Sep 2024
  • RC3: 'Comment on egusphere-2024-823', Anonymous Referee #3, 22 Oct 2024

Interactive discussion

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-823', Anonymous Referee #1, 06 May 2024
  • RC2: 'Comment on egusphere-2024-823', Anonymous Referee #2, 27 Sep 2024
  • RC3: 'Comment on egusphere-2024-823', Anonymous Referee #3, 22 Oct 2024

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload
ED: Reconsider after major revisions (21 Nov 2024) by Xi Yang
AR by Matteo Mastropierro on behalf of the Authors (10 Mar 2025)  Author's response   Author's tracked changes   Manuscript 
ED: Referee Nomination & Report Request started (18 Mar 2025) by Xi Yang
RR by Anonymous Referee #3 (15 May 2025)
ED: Publish subject to minor revisions (review by editor) (09 Jun 2025) by Xi Yang
AR by Matteo Mastropierro on behalf of the Authors (20 Jun 2025)  Author's response   Author's tracked changes   Manuscript 
ED: Publish as is (24 Jun 2025) by Xi Yang
AR by Matteo Mastropierro on behalf of the Authors (07 Jul 2025)  Author's response   Manuscript 

Post-review adjustments

AA: Author's adjustment | EA: Editor approval
AA by Matteo Mastropierro on behalf of the Authors (24 Sep 2025)   Author's adjustment   Manuscript
EA: Adjustments approved (29 Sep 2025) by Xi Yang

Journal article(s) based on this preprint

01 Oct 2025
Drivers of and uncertainty in Amazon carbon sink long-term and interannual variability in CMIP6 models
Matteo Mastropierro, Daniele Peano, and Davide Zanchettin
Biogeosciences, 22, 5231–5246, https://doi.org/10.5194/bg-22-5231-2025,https://doi.org/10.5194/bg-22-5231-2025, 2025
Short summary
Matteo Mastropierro, Daniele Peano, and Davide Zanchettin
Matteo Mastropierro, Daniele Peano, and Davide Zanchettin

Viewed

Total article views: 1,400 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
1,007 248 145 1,400 96 41 64
  • HTML: 1,007
  • PDF: 248
  • XML: 145
  • Total: 1,400
  • Supplement: 96
  • BibTeX: 41
  • EndNote: 64
Views and downloads (calculated since 25 Mar 2024)
Cumulative views and downloads (calculated since 25 Mar 2024)

Viewed (geographical distribution)

Total article views: 1,393 (including HTML, PDF, and XML) Thereof 1,393 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 02 Oct 2025
Download

The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
We address how different ESMs represent vegetation productivity, in terms of carbon fluxes, within the Amazon basin. By statistically assessing the role of climatological and model specific factors that influence vegetation, we showed that surface energy fluxes and the implementation of Phosphorous limitation resulted to be the main drivers of model uncertainties in a future scenario. Reducing these uncertainties allows to increase the reliability of tropical land carbon and climate projections
Share