The new record shows a clear trend of intensification of El Niño events. Central Pacific El Niño activity increased over the late 20th-century while Eastern Pacific El Niños are expected to increase in the future. Until recently, scientists were constrained by temperatures records collected by weather stations and satellites, which were too short to put the recent decadal changes into perspective. In the context of climate change, having a record that extends beyond the centuries is extremely valuable.
According to Freund, there has been an unprecedented increase in the number of El Niños forming in the Central Pacific over the past 30 years, compared to all 30 year periods in the past 400 years.
“We are seeing more El Niños forming in the central Pacific Ocean in recent decades, which is unusual across the past 400 years,” Freund said in a statement.
“There are even some early hints that the much stronger Eastern Pacific El Niños, like those that occurred in 1997/98 and 2015/16 may be growing in intensity.”
The El Niño phenomenon is one of the most important features of the global climate, with serious implications for extreme weather events around the world. Thanks to the coral record, researchers will now be better equipped to model, predict, and plan for future El Niños and their potentially devastating impacts.
“By understanding the past, we are better equipped to understand the future, especially in the context of climate change,” said Dr Freund.
“Prior to this research, we did not know how frequently different types of El Niño occurred in past centuries. Now we do,” said co-author from the Centre of Excellence for Climate Extremes Dr Ben Henley.
The findings were reported in the journal Nature Geoscience.