Wells et al. (2026) Long run emulator calibration increases warming and sea-level rise projections

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Environmental Research Letters
• Year: 2026
• Date: 2026-01-14
• Authors: Chris Wells, Donald P. Cummins, Haozhe He, Chris Smith
• DOI: 10.1088/1748-9326/ae3847

Research Groups

Not available in the abstract.

Short Summary

This study demonstrates that calibrating reduced-complexity climate models with longer Earth system model experiments significantly increases projected long-term global warming and thermosteric sea level rise, particularly under high emissions scenarios.

Objective

• To investigate how the length of Earth System Model (ESM) experiments used for calibration impacts the long-term global warming and sea level rise projections generated by reduced-complexity climate models (emulators).

Study Configuration

• Spatial Scale: Global
• Temporal Scale: Calibration using 150-year versus longer experiments; projections extending to 2100 and 2500.

Methodology and Data

• Models used: Reduced-complexity climate models (emulators)
• Data sources: Abrupt CO2 quadrupling experiments from 17 Earth System Models (ESMs) participating in CMIP6

Main Results

• When calibrated with longer ESM experiments, long-term climate warming projections increase by up to 0.70 °C (0.42–0.93 °C, 25th to 75th percentile) in the median for 2100 under a high emissions scenario.
• Peak global warming in a high overshoot scenario is higher by 0.24 °C (0.14–0.31 °C).
• Corresponding long-term thermosteric sea level rise is higher by 0.45 m (0.22–0.52 m, 25th to 75th percentile) in 2500.
• These results are consistent across calibrations from 17 ESMs.

Contributions

• Demonstrates that the typical 150-year length of CMIP6 abrupt CO2 quadrupling experiments is insufficient for revealing the full equilibrium response to climate forcing, leading to an underestimation of long-term warming and sea level rise projections by emulators.
• Highlights the importance of using longer ESM experiments for more accurate calibration of reduced-complexity climate models, especially for long-term projections.
• Implies that more stringent emissions reductions may be required to limit long-term warming and sea level rise than previously estimated.

Funding

Not available in the abstract.

Citation

@article{Wells2026Long,
  author = {Wells, Chris and Cummins, Donald P. and He, Haozhe and Smith, Chris},
  title = {Long run emulator calibration increases warming and sea-level rise projections},
  journal = {Environmental Research Letters},
  year = {2026},
  doi = {10.1088/1748-9326/ae3847},
  url = {https://doi.org/10.1088/1748-9326/ae3847}
}