Rising seas are threatening coastal communities around the world, which will need billions of dollars to protect themselves. It's clear the water is coming. What's not clear is who pays. This tension is playing out on the shoreline of San Francisco Bay, where the wealthiest companies in the world have built their headquarters next to low-income communities of color. Both need protection, but as cities there plan massive levee projects, they're struggling to figure out what's fair. Will the cost fall on taxpayers or private landowners who benefit the most?NPR climate correspondent Lauren Sommer reports from San Francisco.In participating regions, you'll also hear a local news segment that will help you make sense of what's going on in your community.Email us at considerthis@npr.org.