NASA's Antarctica report raises new questions about sea level rise

Climate circles were abuzz last week after NASA concluded that Antarctica’s ice sheet is, in fact, growing – even as the agency’s models continue to show an overall trend of ice loss amid rising global temperatures.

The surprising news overshadowed an important question for which we currently have no answer: If the ice is thickening, why are oceans continuing to rise? 

The 5.4-million-square-mile Antarctica includes a large interior, which is where more snow now appears to have thickened the ice. But we also know that the Western Antarctica and the Peninsula regions are melting at an ever-increasing rate, something NASA acknowledged in its report.

This melting is considered one of several “climate tipping points” that scientists are watching closely.

At the end of the day, the overall Antarctic melting may now just take a little longer. Any inland ice gains will eventually be overtaken by the melting in other regions if ice loss there speeds up as projected.

This still leaves us with that second and potentially more serious question: If the share of global sea level rise caused by Antarctica’s ice melt is less than originally thought, where is the sea level rise coming from?

Clearly, we continue to look at uncertainty in our ever-changing climate. This is why we must take steps to manage the mounting risks we know we face.