I study the way ice sheets respond to climate change, both in the (distant) past and in the future. I do this using ice-sheet models: computer programs that calculate how much snow falls and melts each year, how much this causes the ice sheet to grow or shrink, and how the ice deforms under its own weight. My research focuses on the interactions between the ice sheet and the rest of the Earth system: when the ice sheet melts, how does this affect the local climate? What's the influence of the melt water on ocean currents? How does the Earth's crust deform under the changing weight of the ice? And in what clever ways can I build these processes into my computer model, so that it's accurate enough to provide useful conclusions, but still fast enough to be able to simulate periods of hundreds of thousands of years?