What a Warm Ocean Means for the Coast We’re Cleaning

Every stretch of sand our cleanup crews clear this year sits on top of a coastline that’s changing faster than it used to. Researchers tracking this year’s El Niño event have documented a warming signal reaching deep into the Gulf of California, with Mexican university scientists monitoring the pattern as one of the more persistent warm-water events on record for the region.¹ That heat doesn’t stay out at sea — it works its way into everything living on the coast, and everything we’re out there picking up after.

Why the Water Matters to the Sand

A warmer ocean physically takes up more space — a basic property of water called thermal expansion — which means sea level creeps upward even without a drop of extra water being added anywhere. Independent ocean-monitoring institutes elsewhere in the Pacific, like Peru’s national marine institute, track exactly this kind of event using a shared scientific standard: a stretch of days where surface temperature sits above the historical 90th percentile for that coastline.² By that standard, the water off both Californias has been running unusually warm for well over a year.

A Coastline With Nowhere Left to Give

On the Baja California side of the same coastline, a peer-reviewed study out of Baja California’s own marine science institutions traced serious erosion at Playas de Tijuana back to a straightforward cause: the beach lost its natural sand supply once upstream dams cut off the sediment the shoreline depended on.³ A beach with no sediment left to rebuild itself has nothing to absorb the extra energy a warmer, higher ocean throws at it — which is exactly the kind of coastline our cleanup and habitat-awareness work exists to support.

Storms Traveling Further Than Ever

Late August brought Hurricane Karina, a major storm that Mexico’s Servicio Meteorológico Nacional tracked forming and rapidly intensifying off southwestern Mexico — never making landfall, but sending dangerous surf and rip currents toward the Baja California Peninsula from well over a thousand kilometers offshore.⁴ Independent Mexican meteorological coverage also noted Karina formed just two days after the previous named storm dissipated in the same waters — a season of systems organizing back-to-back over unusually warm ocean.⁵ Swell like that reaches the coast on days that look calm from the shore, which is part of why our beach-day volunteers are briefed on rip current awareness before every cleanup.