Ice sheets and sea-level rise response

Rapid sea-level rise from ice sheet tipping — particularly the West Antarctic Ice Sheet — poses an existential risk. Preventing this is one possible motivation for researching Stratospheric Aerosol Injection (SAI), as it could reduce sea-level rise contributions from ice sheets relative to a background warming scenario (Moore et al., 2019, 2023, 2024; Goddard et al., 2023). However, the magnitude and durability of this benefit remain uncertain.

The West Antarctic Ice Sheet — and, to a lesser extent, the East Antarctic Ice Sheet — are vulnerable to collapse from climate change, and the pathways through which SAI may affect this are complex. Current research suggests that SAI decreases surface melting and hydrofracturing, but it may not reduce basal melt enough to prevent collapse. SAI may also decrease snowfall on the ice sheet, having an accelerating effect on mass loss (Futerman et al., 2025). The uncertainties associated with these impacts are great and are largely dependent on the scenario chosen.

Current SAI research points toward decreased surface melting on the Greenland Ice Sheet, decreasing its overall contribution to sea-level rise (Moore et al., 2023). A strengthened Atlantic Meridional Overturning Circulation (AMOC), the system of ocean currents that redistributes heat between the tropics and the North Atlantic, might contribute to increased melting of this ice sheet under SAI, but this effect is outweighed by decreased melting from lower surface temperatures (Moore et al., 2019).

This research activity will fund research over multiple years to develop mechanistic understanding of how SAI affects ice sheet dynamics and sea-level rise and to create assessment frameworks that enable rapid evaluation of these impacts across models, injection strategies, and deployment timelines. This research includes, among other activities:

1. Mechanistic understanding through coupled simulations — conducting detailed simulations of SAI in Earth system models (ESMs) coupled to dynamic ice sheet models to isolate the key drivers of ice sheet response. These variables include surface temperatures, ocean temperatures, and snowfall. This will allow researchers to assess how ice sheets respond to different mechanistic changes under varied scenarios.
2. Assessing drivers across GeoMIP simulations — assessing the drivers of ice sheet change in recent GeoMIP simulations across a wide range of models, including the physically motivated metrics being developed by Dr. David Schneider. These tools will create infrastructure for future impact assessments by establishing standardized approaches to measure ice sheet response and its dependence on injection strategy, allowing policymakers to evaluate whether SAI can reliably slow ice sheet melting and, in certain cases, prevent ice sheet tipping.

Reflective has funded the following projects in this area of study:

• Balancing Benefits and Risks: Polar Stratospheric Aerosol Injection and Antarctica's Tipping Points. Dr. Paul Goddard & Dr. Ben Kravitz, Indiana University
• Drivers, observable benchmarks, and teleconnections of Antarctic Ice Sheet mass balance response across SAI simulations. Dr. David P. Schneider, Phare Manchot, LLC (Visiting Scientist at NCAR)
• Evaluating stratospheric aerosol injections to stabilize free-atmosphere precursors of mountain cryosphere tipping points and impacts. Dr. Alfonso Fernández & Dr. Limbert Torrez, Universidad de Concepción