“Wait,” I say. “Can you go back?”
Schwartzenberg obliges and I watch the water pull away. Then she spins the dial again and the ocean throbs inland. I ask her to show me the transition once more, but this time I don’t watch the water—I watch the key to the map instead. Just as I suspected, the jump occurs about 13,000 years ago, during the event glaciologists have labeled Meltwater pulse 1A. During Meltwater pulse 1A, sea levels rose roughly 50 feet over three short centuries. The near-biblical rise in the height of the ocean is directly correlated to the melting of polar ice and the process of deglaciation, the very events that we have begun to witness at the planet’s northern and southernmost reach. Geologists often point to Meltwater pulse 1A as proof that that sea levels, when they change, tend to do so abruptly and with great speed.
Schwartzenberg moves the map into the present, and the colors of the shoreline shift. Any area that once was bay and has been filled is a deep, conifer-colored green. Roads are pink and airports are orange. As she turns up the water levels—adding one foot of rise, then two and three, four, and five—big sections of the city begin to disappear beneath the blue light. Anywhere that once was wetland slips beneath the surface of the Bay.
“It’s totally freaky to see that with just two feet you have lost two airports. Pretty soon all of the approaches to all of the bridges are gone, most of Highway 101 and Route 37, and healthy chunks of the 80,” Schwartzenberg says. The few current pockets of affordability—Alviso, Redwood City, Fremont, Richmond, and East Palo Alto—are all underwater, as are portions of Oakland, Marin County, and downtown San Francisco. What we think of as the coastline is a blur. Looking over the map, I wonder whether the Fisher Bay Observatory is designed to get visitors not just to think about sea-level rise but to begin to imagine the unthinkable: the unsettling of the American shore.
The next afternoon, on the northernmost edge of Alviso, John Bourgeois and I walk along the flat crest of an earthen levee. Much of the town has subsided significantly over the past century, thanks to the groundwater extraction necessary to support water-hungry crops like peaches and almonds. Together we peer into the hollow second story of the former Bayside Canning Company, with its radiant archways and hand-painted murals of women with long black braids carrying fruit to the production line. My gaze rests on the roof gable of a residential home just beyond the ruin. “They might make good candidates for relocation,” I say. If I look left, I am standing five feet above the bay; if I look right, I can peer into this attic.
Bourgeois ignores my comment. “The entire town is 16 feet below sea level,” he says, shaking his head.
To return tidal flow to the area, he has to remove the earthen embankments that separate the ponds from the bay. But before he does that he has to build a four-mile-long replacement levee running all the way from Baylands Park, around Alviso, and over to the Newby Island landfill, for flood protection. “The U.S. Army Corps of Engineers came up with a recommended levee height of 12.5 feet, but their estimate didn’t take sea-level rise into account.” Bourgeois pauses and gives me a look of exasperation. “My employer, the California Coastal Conservancy, and the Santa Clara Valley Water District decided to band together and pay the additional $16 million it would cost to make the levees sea-level-rise ready. That means going up a couple extra feet and making them considerably wider as well.”