We're not saying that CO2 caused this, we're just noting that in the long term, CO2 allegedly causes this

Southern California beach erosion is worst in a decade - latimes.com

Shifting sand is part of a natural cycle that happens each year. Each spring, potent storm surges pull sand from the beaches out to sea. Over the summer, gentler waves gradually push it back ashore.
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Global warming and sea rise are contributing to the deterioration of beaches in the long term, scientists say, but those forces are not to blame for this spring's dramatic changes.