One of the biggest changes to global agriculture is less about the food itself as it is about the water we use to grow it. In some areas, farmers are using freshwater resources - including groundwater - at an alarming rate. The GRACE satellites enable scientists to discover changes to underground aquifers by monitoring changes in the Earth's gravity. In northern India, farmers rely heavily on irrigation to grow crops, and the resulting massive aquifer depletion creates an uncertain future for the region.