Hirasawa et al. (2025) Forcing Susceptibility and Climate Sensitivity to Midlatitude Marine Cloud Brightening

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

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-12-12
• Authors: Haruki Hirasawa, Matthew Henry, Allen S. Mason, Philip J. Rasch, Sarah J. Doherty, Robert Wood, Jim Haywood, Knut von Salzen
• DOI: 10.1175/jcli-d-25-0337.1

Research Groups

Not specified in the provided abstract.

Short Summary

This study uses three Earth system models to evaluate marine cloud brightening (MCB) by injecting sea salt aerosol (iSSA) in 14 ocean regions, identifying a novel midlatitude emission strategy that produces more uniform cooling and precipitation responses, effectively offsetting greenhouse gas warming.

Objective

• To estimate the impact of marine cloud brightening (MCB) implementation in 14 different ocean regions using three Earth system models (ESMs), assessing MCB forcing, cooling efficiency, and patterns of temperature response to identify an optimal iSSA emission strategy for maintaining climates close to present-day conditions.

Study Configuration

• Spatial Scale: 14 distinct ocean regions (e.g., subtropical oceans, midlatitude oceans), with global climate responses assessed.
• Temporal Scale: Focus on short atmospheric lifetime of tropospheric aerosol and comparison to greenhouse gas (GHG) response, aiming to maintain present-day climate conditions.

Methodology and Data

• Models used: Three Earth System Models (ESMs), also referred to as Global Climate Models (GCMs). (Specific model names are not provided in the abstract).
• Data sources: Model simulations, specifically a dataset of 14 MCB simulations performed across the three GCMs.

Main Results

• iSSA emissions in the midlatitude oceans produce stronger cloud forcing and greater cooling efficiency.
• Midlatitude iSSA emissions result in more spatially uniform cooling patterns.
• The novel midlatitude MCB emission strategy produces temperature and precipitation responses across all three ESMs that are similar in pattern (but of opposite sign) to the greenhouse gas (GHG) response.
• Compared to previously tested iSSA injection patterns, midlatitude MCB implementations are more suitable for maintaining climates close to present-day conditions.

Contributions

• Identification of a novel and more effective MCB emission strategy by targeting midlatitude oceans, which better offsets climate warming.
• Reduction of certain unintended negative climate impacts previously found in other MCB modeling studies.
• Development of a dataset comprising 14 MCB simulations across three GCMs.
• Enables the development of more plausible cooperative MCB scenarios.

Funding

Not specified in the provided abstract.

Citation

@article{Hirasawa2025Forcing,
  author = {Hirasawa, Haruki and Henry, Matthew and Mason, Allen S. and Rasch, Philip J. and Doherty, Sarah J. and Wood, Robert and Haywood, Jim and Salzen, Knut von},
  title = {Forcing Susceptibility and Climate Sensitivity to Midlatitude Marine Cloud Brightening},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-25-0337.1},
  url = {https://doi.org/10.1175/jcli-d-25-0337.1}
}