Challenges in Modeling Global Sea Ice in a Changing Environment

Future projections from coupled global climate models suggest the imminent decline of sea ice cover in response to increased greenhouse gas loading in the atmosphere. However, different models vary significantly in the rate and nature of this future decline, with some simulating instances of rapid retreat and others a more gradual reduction. Here I provide an overview of the sea ice components of global climate models and their simulation for present-day and future climate. I assess factors that lead to different simulated sea ice loss across the models, including a discussion of feedbacks that modify the sea ice response to external forcing perturbations. What these results imply for the challenges that we face in modeling the future state of the global sea ice cover is discussed.