Glaciers that drain the West Antarctic ice sheet are thinning, contributing to sea level rise. It is well established that the immediate driver of this thinning is the upwelling of warm Circumpolar Deepwater (CDW) onto the continental shelf, which melts floating ice shelves from below. Less certain is why CDW upwelling has increased in the last few decades. A common idea is that this has been caused by the increased circumpolar westerlies commonly attributed to stratosphere ozone decline, but there is very little evidence to support this. In contrast, there is abundant evidence that changes in the tropical Pacific associated with ENSO influence the local wind field in the West Antarctic region. The local wind field variability in turn drives variability in the flow of CDW onto the continental shelf. Future changes to West Antarctic will depend (at least in part) on what happens in the Tropics in the future.