Investigating Antarctic Ice Sheet-Climate Feedbacks and Climate Justice Implications

Dr. Shaina Sadai

Mar. 21, 2023

3:00 – 4:00 pm MDT

In person in ML-680 (Tower B) and on the CGD YouTube Channel
Main content

This talk will cover two interrelated aspects of my dissertation work: 1) the intersection of scientific modeling, international policy, and climate justice, and 2) an assessment of climate and ice sheet feedbacks from an experiment in which CESM 1.2 was coupled to the Penn State University Ice Sheet model.


The United Nations Paris Agreement states within it an internationally agreed upon goal to limit the global mean temperature (GMT) increase to 2°C above preindustrial levels, and to pursue efforts to limit warming to 1.5°C. However, due to the long-term irreversibility of sea level rise (SLR), risks to island and coastal populations are not well encapsulated by the goal of limiting GMT warming by 2100. Here I will present interdisciplinary work investigating the climate justice implications of the GMT-based goal in light of modeling developments which increase our understanding of climate feedbacks and the spatially variable impact and long temporal commitment to rising seas. The Antarctic Ice Sheet displays dual impacts under a changing climate: (a) Antarctic melt has the potential to cause rapid SLR with a distinct spatial pattern which causes greater impact to members of the Alliance of Small Island States; and (b) future ice sheet melt will result in a negative feedback on GMT, thus delaying temperature rise. When considering these impacts in conjunction, justice concerns associated with the Paris Agreement are exacerbated. A better understanding of the relationship between sea level rise and ice-ocean-atmosphere interactions requires coupled modeling. To further assess both climate feedbacks and the climate justice and policy implications I will present results from future climate simulations in which the Penn State University 3D dynamic ice sheet model has been coupled to the Community Earth System Climate Model, allowing the models to co-evolve on an annual basis. The coupled methodology allows us to assess the impacts of freshwater forcing on climatology as well as the impact of meltwater perturbed climatology on ice sheet evolution and sea level rise contribution from the Antarctic Ice Sheet. This talk will include preliminary findings from a high emissions simulation shedding light on ice sheet stability, climate response, sea level rise contribution, and climate justice.