If you imagine the San Francisco Bay as a bathtub, sea level rise means the bathwater is rising. A new study published today in Science Advances finds the tub is sinking too, and in some places, more than others. Where Bay Area cities have built on landfill or newer mud, that land is compacting, and sinking faster than other places. This subsidence is a problem for, among others, Foster City, Union City, San Rafael, and the land around San Francisco Airport.