By Kayleen Su’e
It is no secret that El Niño events affect weather patterns across the globe. The one question that scientists have though, is how climate change—also known as global warming—will affect El Niño events for generations to come?
A study led by the University of Hawaiʻi at Mānoa’s Bin Wang — a member at the International Pacific Research Center )– and several international climate researchers, revealed that since the 1970’s, El Niño events have been shifting from the eastern Pacific to the western Pacific. This study has been published in the Proceedings of National Academy of Science and it informs the general population of more frequent and extreme El Niño events that will inevitably happen due to continued warming over the western Pacific ocean.
From 1901 to 2017, the team evaluated 33 El Niño events and examined how they developed, where they developed, the onset location of the warming, and how strong they’ve gotten over the years, according to a news story from the university
Scientists found that by grouping together El Niño events with similar developmental features, they could identify four different types of El Niños. These particular El Niño events stood out because they had very distinct onset locations and strengthening patterns. The team noticed that from the 1970’s onwards, El Niño events have not only gotten stronger, but they’ve also shifted from the eastern Pacific to the western Pacific. Out of five extreme El Niño events that were recorded, only one happened before the 1970’s.
Wang and his team found that the factors controlling these shifts are because of sea surface temperatures in the western Pacific warm pool and the easterly winds in the Central Pacific. From these variables, they predicted that future El Niño events will only become more frequent.
“Simulations with global climate models suggest that if the observed background changes continue under future anthropogenic forcing, more frequent extreme El Niño events will induce profound socioeconomic consequences,” reports Wang, (October 2019, UH News).
Some socioeconomic consequences include: severe droughts in western Pacific Islands and Australia that cause wildfires and famine, northern coasts of South America facing flooding from excessive rainfall, warmer ocean temperatures impacting fisheries and coral reefs globally. Hawai’i is typically impacted with heavy rainfall, hurricane activity, fluctuations in air and sea temperatures, and fluctuating sea levels.
Wildfire in Aberdare, New South Wales, Australia. (Photo credit: Quarrie Photography, CC BY-NC-ND 2.0)