For the cities shown on the map regarding sea level rise scenarios, the impacts can be categorized into three types:
- Flooded: Cities situated at very low elevation close to current sea level, especially on coastlines, are likely to be flooded by the rise in sea levels. This includes areas already vulnerable to storm surges and extreme weather events that intensify flooding risks.
- Not flooded but much closer to the shoreline: Some cities, while not initially flooded, will experience significant shoreline retreat due to rising seas. These cities will be much closer to the water line, increasing vulnerability to coastal erosion, flooding during storms, and reduced land availability.
- No significant flooding or shoreline proximity change: Cities located sufficiently inland or at higher elevations will not experience flooding or significant impacts on their shoreline proximity due to sea level rise.
Key factors include local elevation, natural protections such as dunes or mangroves, existing flood defenses, and the rate of sea level rise combined with land subsidence or growth. Cities on the east coast of the U.S. (like New York City and Miami), some Asian cities (Bangkok, Kolkata), and others listed in studies are at high risk of flooding or becoming much closer to the shoreline by mid-century due to expected global sea level rise combined with local effects like sinking land or increased storm frequency.