Humans are reshaping the Earth. Not just the climate of Earth, but the planet itself. As the Earth warms due to human interference with the climate, the oceans rise. And covering more than two thirds of the planet’s surface it means the rising oceans are literally changing the shape of the planet we call home. And since the early 1990s, a single series satellites has captured this change with unbelievable accuracy. Built to measure changes in ocean currents, our sea level satellites have revolutionized our understanding of the oceans and now provide one of the most important records of how fast our climate is changing. The unprecedented success of these missions has led to the development of the Jason-CS Mission, which includes the recently launched Sentinel-6 Michael Freilich satellite. This US-European collaboration includes two satellites, launched 5 years apart, and will guarantee another full decade of sea level observations. In addition, the upcoming SWOT mission will improve the resolution of sea level measurements, allowing oceanographers to explore new ocean physics. SWOT will also provide unprecedented coverage of lake and river observations, likely touching off a similar revolution in the field of hydrology.

Josh Willis is the lead NASA scientist for the US and European Jason satellite missions that measure sea level, and the recently launched Sentinel-6 Michael Freilich satellite that will help carry this legacy through the rest of the coming decade. Willis is an expert in sea level rise and its causes. He is also the lead scientist for NASA’s airborne mission Oceans Melting Greenland (OMG for short!). He enjoys using comedy to communicate about climate change has has been known to tell the occasional or sing a song to help people understand why the climate is changing.