Dear Columnist,
We just found out that ninety percent of coastal hazard assessments used the wrong baseline. The ocean was a foot closer to us than anyone official ever said. In parts of the Global South, three feet closer. Our seawalls, our zoning maps, our insurance models, our arguments before international funding bodies. All of it built on a number that was wrong before the first projection was ever run. We have been planning around a coastline that does not exist. How do we start over?
Sincerely, A Coastal City of 4.2 Million
Dear Coastal City,
Download the corrected open-access dataset the researchers published in Nature this month. Commission a local reassessment using tide-gauge records rather than satellite-derived models. Review your seawall specifications against measured water levels. Press your planners to confirm they are using site-specific data. Some responsible local engineers already know where the water actually is. You should find this reassuring. We do.