California beaches will experience severe erosion by 2100

As much as 67 per cent of Southern California beaches may become completely eroded by the year 2100, unless humans take measures to conserve these iconic locations, scientists have warned.
Scientists from US Geological Survey used a newly developed numerical model used to predict shoreline-change due to both sea level rise and changing storm patterns driven by climate change called "CoSMoS-COAST".
The model took into consideration sand transport both along the beach (due to longshore currents) and across the beach (cross-shore transport) by waves and sea-level rise.
The CoSMoS model used information about historical shoreline positions and how beaches change in response to waves and climate cycles such as El Nino, to improve estimates and improve confidence in long-term prediction of coastline changes in Southern California.

Although a majority (72 per cent) of beaches in Southern California show historical trends of getting larger due to large artificial beach nourishments since the 1930s, future predictions indicate that nearly all of the beaches will experience erosion and get smaller due to accelerated sea-level rise, researchers said.
"The prospect of losing so many of our beaches in Southern California to sea level rise is frankly unacceptable. The beaches are our public parks and economic heart and soul of our coastal communities," said John Ainsworth California Coastal Commission Executive Director.

"We must do everything we can to ensure that as much of the iconic California coast is preserved for future generations," Ainsworth said.

"Beaches are perhaps the most iconic feature of California, and the potential for losing this identity is real," said Sean Vitousek of US Geological Survey.
"Losing the protecting swath of beach sand between us and the pounding surf exposes critical infrastructure, businesses and homes to damage," Vitousek said.
"Beaches are natural resources, and it is likely that human management efforts must increase in order to preserve them," he said.
The study was published in the Journal of Geophysical Research.