The Pacific Coast Highway, an iconic symbol of California and vital transportation route, runs along the state’s coastline from Dana Point in Orange County to Leggett in Mendocino County. But this highway and hundreds of other permanent structures along the coast are at great risk for falling into the sea as the Pacific Ocean rises.

The questions of how much sea level rise we can expect, how we balance public and private concerns in addressing coastal changes and how we can reduce the chances of even more catastrophic sea level rise were at center stage during a Zócalo/UCLA Downtown event titled “What Will California’s Coastline Look Like in 2100?” The event, moderated by Rosanna Xia, environment reporter for the Los Angeles Times, took place before a standing-room only audience at the National Center for the Preservation for Democracy.

The panel included Alex Hall, director of the UCLA Center for Climate Science; Sean Hecht, co-executive director of the Emmett Institute on Climate Change and the Environment at UCLA School of Law; and Effie Turnbull Sanders, member of the California Coastal Commission.

Xia opened the event by asking: Why is the sea rising?

Hall broke down the causes of sea level rise over the past century by percentage: 45 percent of the rise has occurred because the ice sheets and mountain glaciers are melting. Another 45 percent is because, as the ocean has warmed, “thermal expansion of sea water” has occurred, literally expanding the size of the ocean. “The final 10 percent,” Hall said, “comes from the drawdown of aquifers,” from which we draw water to irrigate crops. This water that once was underground instead ends up in streams and rivers that flow into the ocean.

Read the full story at Zócalo Public Square.