Julius Oelsmann study finds coastal cities sinking, local seas rising
A new study out this week says some of the world's biggest cities are actually sinking under their own weight, and it's making rising sea levels even worse.
Led by Dr. Julius Oelsmann from Munich, the research found that coastal cities are seeing sea levels go up about 6mm every year, three times faster than the global average.
All this is happening because heavy buildings, plus too much groundwater and oil extraction, are causing the ground to sink, putting millions at higher risk of flooding.
Jakarta subsides nearly 14mm annually
Jakarta tops the list, dropping nearly 14mm a year (with some spots sinking even faster).
Other cities like Tianjin, Bangkok, Lagos, and Alexandria aren't far behind with subsidence rates between 4 and 13.5mm annually.
Tokyo stands out as a success story: thanks to Japanese government policies that introduced new water resources, its sinking rate once surpassed 10mm annually in the worst areas, but government water policies later curbed it.
The researchers say tackling both land subsidence and sea-level rise is key if we want to protect coastal communities in the future.