El Nino has been impacting global climate for 250 million years

Using advanced climate modeling techniques, the team simulated Earth's climate at various points over the last 250 million years. modelling

In Short

• ENSO cycle persisted even when continents were in radically different configurations
• The study employed the same climate modeling tool used by the IPCC
• Researchers adapted it to look backwards in time

A new study by Duke University researchers has uncovered evidence that the El Nino-Southern Oscillation (ENSO) phenomenon, known for its significant impact on global weather patterns, has been a feature of Earth's climate for at least 250 million years.

The research, published in the Proceedings of the National Academy of Sciences, suggests that these climate oscillations were often more intense in the distant past than they are today.

Using advanced climate modeling techniques, the team simulated Earth's climate at various points over the last 250 million years.

Their findings reveal that the ENSO cycle persisted even when continents were in radically different configurations, such as during the time of the supercontinent Pangea.

"In each experiment, we see active El Niño Southern Oscillation, and it's almost all stronger than what we have now, some way stronger, some slightly stronger," explained Shineng Hu, assistant professor of climate dynamics at Duke University's Nicholas School of the Environment.

The study employed the same climate modeling tool used by the Intergovernmental Panel on Climate Change (IPCC) for future climate projections. However, the researchers adapted it to look backwards in time, creating 26 "slices" of 10-million-year periods.

These simulations accounted for various factors influencing ancient climates, including different continental arrangements, solar radiation levels, and atmospheric CO2 concentrations. The results highlight the resilience and variability of the ENSO phenomenon across vastly different global conditions.

Two key factors emerged as crucial in determining the magnitude of these ancient El Niño events: the thermal structure of the oceans and the "atmospheric noise" created by ocean surface winds.

This finding demonstrate the importance of considering both oceanic and atmospheric factors in understanding climate oscillations.

The research has significant implications for our understanding of current and future climate patterns. By revealing the long-term persistence and variability of ENSO, it provides valuable context for interpreting modern climate change and improving future climate projections.

As Hu emphasises, "If we want to have a more reliable future projection, we need to understand past climates first." This study not only sheds light on Earth's climatic history but also offers crucial insights that could enhance our ability to predict and prepare for future climate scenarios.