A new study from UC San Diego Scripps Institution of Oceanography researcher emeritus Peter Bromirski used nearly a century of data to show that the average heights of winter waves along the California coast have increased as climate change has heated up the planet.
Findings revealed California’s average winter wave height from 1970 on has increased by 13% or about one foot compared to average winter wave height between 1931 and 1969.
“After 1970, there is a consistently higher rate of large wave events,” Bromirski said. “It’s not uncommon to have a winter with high wave activity, but those winters occurred less frequently prior to 1970.”
Bromirski also found that between 1996 and 2016 there were about twice as many storms that produced waves greater than 13 feet along the California coast in comparison to those from 1949 to 1969.
The study, published this week in the Journal of Geophysical Research – Oceans, drew from seismic records dating back to 1931 to infer wave height, a method first developed by Bromirski in 1999. The analysis joins a growing body of research suggesting storm activity in the North Pacific Ocean has increased under climate change.
If average winter waves continue to get bigger, it could amplify the effects of sea-level rise and have significant implications for flooding and erosion along California’s coast, according to researchers.
“Waves ride on top of the sea level, which is rising due to climate change,” Bromirski said. “When sea levels are elevated even further during storms, more wave energy can potentially reach vulnerable sea cliffs, flood low-lying regions or damage coastal infrastructure.”
