Came across a Nature Climate Change study this week that explained something I'd been half-noticing for years. Of 18 coastal megacities studied, 67% have lost sea breeze days over the past few decades. New York is down about 29%. Miami, London, and Shanghai are all in the same camp.

The mechanism is straightforward once you see it. A sea breeze happens because land heats up faster than the ocean during the day, and air flows in from the cooler water to fill the gap. As sea surface temps keep rising, that gap shrinks. Less differential, less breeze.

And the downstream effects are more interesting than just stuffier afternoons. Sea breezes have been one of the big natural cooling systems for coastal cities. Losing them stacks more urban heat stress on top of the obvious warming, lets air pollution sit longer, and even drops the output potential of nearby offshore wind.…