According to a recent study published in the journal Nature Cities, 28 of the most populous U.S. cities are sinking. It’s due to a phenomenon called land subsidence, exacerbated in many cases by humans extracting too much groundwater from underground aquifers. Ali Rogin speaks with Grist senior writer Matt Simon to learn more. PBS News is supported by - https://www.pbs.org/newshour/about/funders. Hosted on Acast. See acast.com/privacy