Stratospheric Aerosol Injection Can Reduce Risks to Antarctic Ice Loss Depending on Injection Location and Amount

Journal Article · 14 November 2023 · Journal of Geophysical Research. Atmospheres (Online)

DOI: https://doi.org/10.1029/2023JD039434 · OSTI ID:2332923

Goddard, Paul B. ^[1]; Kravitz, Benjamin S.  ^[2]; MacMartin, Douglas G. ^[3]; Visioni, Daniele ^[3]; Bednarz, Ewa Monkia ^[3]; Lee, William R. ^[4]

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1. Indiana University, Bloomington, IN (United States)
2. Indiana University, Bloomington, IN (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
3. Cornell University, Ithaca, NY (United States)
4. Cornell University, Ithaca, NY (United States); National Center for Atmospheric Research (NCAR), Boulder, CO (United States)

Owing to increasing greenhouse gas emissions, the Antarctic Ice Sheet is vulnerable to rapid ice loss in the upcoming decades and centuries. Here this study examines the effectiveness of using stratospheric aerosol injection (SAI) that minimizes global mean temperature (GMT) change to slow projected 21st century Antarctic ice loss. We simulate 11 different SAI cases which vary by the latitudinal location(s) and the amount(s) of the injection(s) to examine the climatic response near Antarctica in each case as compared to the reference climate at the turn of the last century. We demonstrate that injecting at a single latitude in the northern hemisphere or at the Equator increases Antarctic shelf ocean temperatures pertinent to ice shelf basal melt, while injecting only in the southern hemisphere minimizes this temperature change. We use these results to analyze the results of more complex multi-latitude injection strategies that maintain GMT at or below 1.5°C above the pre-industrial. All these multi-latitude cases will slow Antarctic ice loss relative to the mid-to-late 21st century SSP2-4.5 emissions pathway. Yet, to avoid a GMT threshold estimated by previous studies pertaining to rapid West Antarctic ice loss (1.5°C above the pre-industrial GMT, though large uncertainty), our study suggests SAI would need to cool about 1.0°C below this threshold and predominately inject at low southern hemisphere latitudes (~15°S - 30°S). These results highlight the complexity of factors impacting the Antarctic response to SAI and the critical role of the injection strategy in preventing future ice loss.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF); National Oceanic & Atmospheric Administration (NOAA)
• Grant/Contract Number: AC05-76RL01830
• OSTI ID: 2332923
• Report Number(s): PNNL-SA--195037
• Journal Information: Journal of Geophysical Research. Atmospheres (Online), Journal Name: Journal of Geophysical Research. Atmospheres (Online) Journal Issue: 22 Vol. 128; ISSN 2169-8996
• Publisher: American Geophysical UnionCopyright Statement
• Country of Publication: United States
• Language: English