Satellite Gravimetry:
a unique tool for monitoring climate change

The determination of global mass transport phenomena via gravity field monitoring from satellites is an essential method to tackle the environmental and societal challenge of climate change. Indeed, previous and current space missions (e.g. GRACE, GOCE and GRACE-FO) revolutionised the understanding of mass transport in the Earth system, enabling for the first time the recovery of a global time-varying gravity field. The data obtained in missions so far provides unique and invaluable contributions for understanding climate change processes, such as the melting of the glaciers and ice sheets, sea-level rise, regional droughts, and flooding, and potentially allow for the early warning of such events. The largest error contributor of state-of-the-art missions is linked to the effect of aliasing which results from their incomplete observation geometry. The next generations of gravimetry missions will improve the spatiotemporal sampling of the gravity signal using well-designed satellite constellations, but remain limited in accuracy and resolution. To go one step further, a technological breakthrough involving novel sensors is at hand. It will provide a significant step forward in accuracy. This improvement would pave the way for a global and repetitive remote sensing of essential climate variables related to ocean, cryosphere, atmosphere and land hydrology and monitoring geodynamics phenomena related to earthquakes and volcanic eruptions.