During the 20th century we observed a poleward shift and an increase in strength of the westerly winds over the Southern Ocean, which can be largely attributed to stratospheric ozone depletion and greenhouse gas emissions. At equilibrium these changes in the winds are expected to cause a decrease in sea ice extent. However, the observational record shows an expansion of sea ice. A two-timescale response has been proposed to resolve this dichotomy; over short timescales anomalous surface Ekman transport cools the sea surface and increases sea ice extent, while over long timescales the upwelling of warm subsurface water causes an increase in sea surface temperature and a reduction in sea ice extent. Using observations and models I explore the surface and subsurface response of the Southern Ocean to changes in the westerly winds over a range of timescales from months to decades.