UT researchers examine potential changes in El Niño from climate change

Katy Nelson, Senior News Reporter

University researchers drilled for ancient corals off the South Pacific Ocean to find out how the climate pattern of El Niño might change as a result of climate change. Although they received inconclusive results that were published in a study on March 4, the researchers intend to trace El Niño’s history further back in time.

El Niño and La Niña are “climate patterns in the Pacific Ocean that can affect weather worldwide,” according to the National Ocean Service. El Niño occurs about every three to four years and pushes warm water back east to the west coast of the Americas as a result of changing wind patterns. This leads to warm surface water, significantly warmer temperatures and flooding throughout the Americas.

Allison Lawman, a postdoctoral associate at the Cooperative Institute for Research and Environmental Sciences at the University of Colorado Boulder, said she and the team of scientists wanted to learn how El Niño will change in the future as a result of climate change. 

“We don’t have a crystal ball, we can’t look into the future, but we can look at the past,” Lawman said. “We can look at how El Niño changed under different background conditions that are very different today.” 

Several of the researchers traveled to the island nation of Vanuatu in the South Pacific Ocean at the end of 2019 to drill for ancient corals located under the island’s reef. Jud Partin, a research scientist and lecturer at the Institute of Geophysics, said they are visiting the island again at the end of this year or in early 2023, and they hope to find corals tracing back to the Last Glacial Maximum, which was about 20,000 years ago.  

“Earth’s climate was about seven degrees Celsius colder,” Partin said. “Likely, that impacted El Niño. The idea would be to get these corals that grew a long time ago, measure their composition and then take this computer model that we have the ability to change the conditions of and have it set to those past conditions.” 

The researchers utilized the University supercomputer Lonestar5 to run various simulations, including one of the Earth’s climate during different time periods over the last 9,000 years, Lawman said. 

Lawman said researchers can get a better idea of what to expect in the next hundred years for El Niño by comparing the data they receive from the simulations of past patterns.

Partin said the team received inconclusive results from their research because of the irregularity of El Niño during the intense climate changes.

“Earth has been warming over forty years, there’s been a whole string of El Niños that are really big, and people want to know, is it connected?” Partin said. “Unfortunately, the jury is out because we need to basically average all those jackhammers and see if it is a change or not.” 

Partin said the researchers plan to go back further in time because of the changes to Earth’s climate, and the researchers hope they will find the changes in El Niño to be similar. 

“Inquiring minds want to know,” Partin said. “If El Niño is getting stronger by some appreciable amount, we need to know that and prepare for that, as it impacts every country that’s around the Pacific Ocean — the U.S. included.”