Ancient El Niños reveals limits to future climate projections

Scientists will have a hard time detecting signs of global warming because of the climate pattern El Ni.

Scientists at The University of Texas at Austin analyzed 9,000 years of Earth's history. One of the world's most powerful supercomputers was used by the scientists to conduct their research.

The study of the past, which was recently published in Science Advances, was motivated by the need to get a clearer picture of how climate change may affect El Ni.

Every few years for weather patterns worldwide, the stage is set by the warm phase of the El Niño Southern Oscillation. The strongest El Ni events, such as the ones in 1997 and 2015 that brought wildfires to the rainforests of Borneo in Asia and caused widespread bleaching to the world's coral reefs, happen about once a decade.

Computer models are not sure if El Ni will become stronger or weaker as the world warms.

The study's lead author, Allison Lawman, who began the research as a PhD, said that much of the world's temperature and rainfall are influenced by what happens in the tropical Pacific Ocean.

Lawman and her colleagues used the Lonestar5 supercomputer at UT's Texas Advanced Computing Center to run a series of climate simulations of a period in Earth's history before human influences, when the main source of climate change came from a tilt in the planet. Lawman had previously developed a coral emulator that could be used to compare the simulations with climate records from ancient corals.

The occurrence of strong El Ni events increased over time, but the change was small compared with El Ni.

It is like trying to listen to soft music next to a jackhammer, according to study co-author Jud Partin.

To achieve this, Partin, Lawman and the study's other authors call for further investigations into the last ice age to see how El Ni will respond to more intense changes in climate forces.

Scientists need to keep pushing the limits of models and look at geological intervals deeper in time that could offer clues on how sensitive El Ni is to changes in climate.

More information: Allison E. Lawman et al, Unraveling forced responses of extreme El Niño variability over the Holocene, Science Advances (2022). DOI: 10.1126/sciadv.abm4313 Journal information: Science Advances Citation: Ancient El Niños reveals limits to future climate projections (2022, March 15) retrieved 17 March 2022 from https://phys.org/news/2022-03-ancient-el-nios-reveals-limits.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.