Abstract
In light of the rapid recent retreat of Arctic sea ice, the possibility that the ice-albedo feedback may drive an irreversible tipping point has garnered considerable attention. In this talk, I'll present the results of an investigation into the possibility of such a tipping point by examining the central physical processes associated with the loss of Arctic sea ice. Starting with basic physical principles, I use a series of standard mathematical approximations to arrive at an idealized representation of the coupled Arctic climate system, and then I perform a bifurcation analysis to look for threshold behavior involving sudden jumps. At the end of the talk, I'll summarize other current and recent research which focuses on (i) large-scale Arctic sea ice and (ii) abrupt climate change in the North Atlantic during the past 100,000 years.