Some erosion on Dania Beach. The OED defines cliffing as the climbing of cliffs. And notes that its usage is rare. Merriam-Webster and the American Heritage have nothing to say. Wiktionary, however, addresses the meaning above: "the formation of cliffs." It offers this quote from Eric C. F. Bird, Coastal Geomorphology: An Introduction:
"Cliffing (scarping) of the seaward margins of coastal dunes and the absence of new fore dunes (or the formation of new fore dunes lasting at most a few years) is very widespread around the world’s coastline, a consequence of the modern prevalence of beach erosion."