New research has found that El Niño events, a warming pattern in the Pacific Ocean that can mean wetter winters for California’s Central Coast, have become more and more intense since the Industrial Revolution.
Samantha Stevenson, an associate professor at UC Santa Barbara studying climate modeling, coauthored the study that was recently published in the journal Science.
She told KCBX that before this research, scientists weren’t sure whether El Niño conditions — and its counterpart, La Niña conditions — were increasing in intensity.
“I've actually been thinking about this question for like 15 years now, and it's been pretty unclear,” Stevenson said.
“Part of the problem is that we get to these El Niño events every three to seven years or so,” she said. “That's pretty infrequent compared to the timescale that we've been observing the ocean with high-quality oceanographic instrumentation.”
Stevenson’s study used temperature records taken from coral reef samples going back a thousand years to understand the state of the ocean and climate over that period.
“Around the time when we know that humans really started modifying the climate, the variability in those coral records also started taking off,” Stevenson said.
Variability refers to the climate’s ability to fluctuate over time, shifting between warm and cool years, or wet and dry spells, over a long-term average.
The researchers found that swings between El Niño and La Niña events have become stronger and stronger.
“The variability is more intense over the last 50 years than at any point over the last thousand, which is pretty remarkable as an indication of this intensification of El Niño,” Stevenson said.
Stevenson says more research is needed to know if and how climate change might be contributing to this pattern.
On top of extra precipitation and increased risk of storms and flooding in Southern California, El Niño events can lead to drought in other parts of the world, like South East Asia and Central America.
Officials have warned that this year’s El Niño could break records. According to the World Meteorological Organization, current conditions will continue to intensify, and could lead to extreme weather events over the next several months.
