Abstract
Emissions-driven (prognostic CO2) simulations are essential for representing two-way carbon-climate feedback in Earth System Models. We present an emissions-driven land–atmosphere coupled biogeochemistry (BGC) configuration (BGCLNDATM_progCO2) in version 2.1 of the Energy Exascale Earth System Model (E3SMv2.1). This is the first E3SM configuration that performs land-atmosphere emission-hindcasts. Here, we document its implementation, evaluate the model's performance against observations and other models, and propose a structured evaluation protocol for such emissions-driven simulations. We conducted transient historical simulations (1850–2014) with BGCLNDATM_progCO2 and compare them to reference simulations—a land-atmosphere coupled simulation without BGC and a standalone land simulation with BGC, both using prescribed CO2 concentrations—and to observations. BGCLNDATM_progCO2 overestimates atmospheric CO2 concentrations by 11–23 ppm yet stays within the 40-ppm spread CMIP6 emission-driven models and retains physical climate properties comparable to the reference runs. The CO2 biases are partly attributed to underrepresented oceanic CO2 uptake and inadequate representations of some terrestrial processes. In general, introducing prognostic CO2 did not change physical climate metrics at the global scale but had larger regional effects, particularly over land where spatially heterogeneous CO2 and prognostic leaf area index influenced surface energy balance. Finally, we propose a general evaluation protocol including spin-up assessment, atmospheric CO2 benchmarking, physical climate evaluation, and land biogeochemical analysis to support scientific rigor and facilitate inter-model comparisons. The new configuration lays the groundwork for future enhancements, including improved terrestrial biogeochemical processes, integrated marine biogeochemistry, and additional human–Earth system interactions. These developments advance E3SM toward fully coupled emissions-driven simulations, enabling more accurate carbon–climate feedback projections and informing mitigation policy by providing physically consistent carbon-budget metrics for mitigation scenarios.
| Original language | English |
|---|---|
| Article number | e2025MS005099 |
| Journal | Journal of Advances in Modeling Earth Systems |
| Volume | 17 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2025 |
Funding
This research was supported by the E3SM project, funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research Earth System Model Development (ESMD) program area. E3SM production simulations were performed on a high‐performance computing cluster provided by the BER ESM program and operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy under Contract DE‐AC0576RL01830. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE‐AC52‐07NA27344. Oak Ridge National Laboratory (ORNL) is managed by UT‐Battelle, LLC, for the U.S. Department of Energy under Contract DE‐AC05‐00OR22725. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy (Contract 89233218CNA000001). Lawrence Berkeley National Laboratory which is managed and operated by the Regents of the University of California for the U.S. Department of Energy under prime contract number DE‐AC02‐05CH11231. This paper describes objective technical results and analyses. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. We thank the three anonymous reviewers and the editor for their insightful comments and constructive feedback, which help to improve the clarity and quality of this manuscript. This research was supported by the E3SM project, funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research Earth System Model Development (ESMD) program area. E3SM production simulations were performed on a high-performance computing cluster provided by the BER ESM program and operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy under Contract DE-AC0576RL01830. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344. Oak Ridge National Laboratory (ORNL) is managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract DE-AC05-00OR22725. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy (Contract 89233218CNA000001). Lawrence Berkeley National Laboratory which is managed and operated by the Regents of the University of California for the U.S. Department of Energy under prime contract number DE-AC02-05CH11231. This paper describes objective technical results and analyses. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. We thank the three anonymous reviewers and the editor for their insightful comments and constructive feedback, which help to improve the clarity and quality of this manuscript.
Keywords
- E3SM
- Earth system modeling
- emission-driven
- evaluation protocol
- land-atmospheric interactions
- prognostic CO