A friend recently asked me, "so, are you bullish on Miami yet, or are you still worried about the water?" And my response was that I love Miami, but that I do think about the risk of climate change.

Then today, another friend sent me this study by scientists at the University of Miami showing that 35 buildings along the Miami Beach to Sunny Isles Beach coastline experienced some degree of subsidence between 2016 to 2023. In other words, they sunk into the ground a little.

Here's how they measured this:

The study published December 13, 2024, in the open-access journal Earth and Space Science, of the American Geophysical Union, employed a satellite-based technique known as Interferometric Synthetic Aperture Radar (InSAR). By combining 222 SAR images from the European Sentinel-1 satellites, the research team created a surface displacement time series. The technique utilizes "persistent radar scatterers" as reference points for measurement. These scatterers include fixed elements on a structure such as building balconies, rooftop air conditioning units, and boardwalks, which reflect the radar signal back to the satellite antenna. Satellites flying at 700 kilometers above Earth can measure millimeter-scale displacements.

Now, some degree of subsidence is normal. But apparently, not this much:

“The discovery of the extent of subsidence hotspots along the South Florida coastline was unexpected,” said Farzaneh Aziz Zanjani, the study’s lead author, a former post-doctoral researcher and alumna of the Rosenstiel School. “The study underscores the need for ongoing monitoring and a deeper understanding of the long-term implications for these structures.”

So yeah, I'm still worried about the water. It's something I would need to get a lot smarter on in order to feel comfortable.