A Framework for Minimizing Remote Effects of Regional Climate Interventions: Cooling the Great Barrier Reef Without Teleconnections

[Geoengineering News]

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL113191

Authors

Will Krantz, J. David Neelin, Fiaz Ahmed

First published: 21 May 2025

https://doi.org/10.1029/2024GL113191

Abstract

Climate interventions like Marine Cloud Brightening have gained attention for their potential to protect vulnerable marine ecosystems from the worst impacts of climate change. Early modeling studies raised concerns about potential harmful global side effects stemming from regional interventions. Here we propose a modeling framework to evaluate these risks based on using maximal deployment scenarios in a global climate model to identify potential pathways of concern, combined with more realistic large intervention levels. We demonstrate this framework by modeling a cooling intervention over the Great Barrier Reef using the Community Earth System Model. We identify potential impacts on tropical convection that could produce remote impacts, and show that limiting intervention duration to deployment in the key season largely eliminates these risks. Overall we illustrate that the local ecological goals can be achieved at a level of cooling well below what poses a risk of significant remote effects.

Key Points

General circulation modeling reveals that a regional cooling over the Great Barrier Reef has a low risk of producing remote impacts

One plausible teleconnection pathway can be avoided by limiting cooling interventions to the summer season

We propose a general modeling approach for identifying and mitigating the risk of remote impacts from regional cooling interventions

Plain Language Summary

Brightening clouds or the surface of the ocean over sensitive marine ecosystems could create a cooling effect and help protect them from the most damaging impacts of climate change. Some studies have shown that cooling large regions of the ocean could alter atmospheric circulation and create undesirable side effects outside the intended region of intervention. In this study we propose a framework for using global climate models to evaluate the risks of these remote side effects by simulating a range of cooling scenarios. We demonstrate using this framework in the specific case of cooling the ocean around the Great Barrier Reef, and find that strong year-round cooling could produce remote impacts by reducing tropical convection. By limiting cooling to the hottest months of the year and a realistic intensity of cooling, these remote impacts are avoided.

Source: AGU