New and groundbreaking research conducted by oceanographer Peter Bromirski at the Scripps Institution of Oceanography has shed light on an alarming trend: the escalation of wave sizes along the California coastline. As our planet experiences global warming, waves towering at a minimum of 13 feet (approximately 4 meters) are becoming a more regular occurrence.
Bromirski's innovative approach involved delving into seismic records dating back to 1931, harnessing the ripple effect generated when waves collide with the shore and create energy that registers on seismographs. While prior data relied on buoys from the National Oceanic and Atmospheric Administration, this study took a different path.
Bromirski and his team meticulously digitized decades' worth of winter seismic readings, providing an unprecedented look at nearly a century of wave evolution. The findings are remarkable: average wave heights during winter have surged by nearly a foot since the presumed onset of accelerated global warming in 1970. What's more, swells reaching at least 13 feet in height are now occurring twice as frequently between 1996 and 2016 compared to the period from 1949 to 1969. This transformation in wave patterns holds significant implications. As Bromirski underscored, it contributes to intensified erosion, coastal flooding, and infrastructure damage. When coupled with the rising sea levels, the phenomenon of larger waves amplifies the frequency of these adverse events, prompting the need for heightened awareness and proactive measures.
The impact of changing waves extends beyond their size, as revealed by recent research.
“Since 1970, we've observed twice as many significant wave events compared to earlier times,” explained Bromirski, highlighting the escalating trend.
Published in the Journal of Geophysical Research: Oceans, the study adds weight to the growing body of evidence linking climate change to profound shifts in ocean dynamics. Wave height isn't the only factor altering; waves are also gaining potency.
The consequences of this transformation are already evident. During the recent winter, California bore the brunt of severe storms and immense waves, resulting in cliff collapses, pier damage, and inundated sections of the iconic Highway 1.
According to Bromirski, this foreshadows the future. As global warming potentially accelerates, we can anticipate even more substantial waves. With rising sea levels and intensified storms, coastal communities will confront amplified flooding, vanishing beaches, triggered landslides, and compromised bluffs.
This concern is acutely pronounced along California's coastline, where sea cliffs have already crumbled, leading to home collapses in recent years. The study projects that by the close of the 21st century, even moderate waves could wreak damage comparable to the devastation caused by extreme weather events.
Oceanographer Gary Griggs, from the University of California Santa Cruz, noted that a one-foot increase in wave height over 50 years might not seem monumental, yet it aligns with what scientists comprehend about the world's warming oceans. They're becoming progressively more turbulent due to intensified storms, causing havoc along coastlines.
While not part of this research, Griggs emphasized that these findings dovetail with mounting scientific evidence depicting the swift pace of global warming and sea level rise. “The challenge,” he noted, “is determining how to effectively address these changes.”