New Model Reveals El Niño Has Strengthened for the Past 5000 Years

El Niño has the potential to drastically impact our environment. It's not a contemporary phenomenon, though. Fishermen off of the coast of Peru first noticed El Niño, when water turned warm and rain continuously fell, hundreds of years ago. Now, scientists are taking a closer look at El Niño to see how it will respond to a warming climate.

"We can't see the future; the only thing we can do is examine the past," said Zhengryu Liu, one of the researchers, in a news release. "The question people are interested in now is whether it's going to be stronger or weaker, and this requires us to first check if our model can simulate its past history."

The scientists examined what has influenced El Niño over the last 21,000 years in order to better understand and prepare for consequences. More specifically, they used state-of-the art computer models to see how El Niño has reacted over the last 6,000 years. The model examined the large-scale influences that have impacted the strength of El Niño, such as atmospheric carbon dioxide, ice sheet melting and changes to Earth's orbit.

During El Niño, the trade winds relax and the sea surface temperature differences between the western and eastern Pacific Ocean diminish. This alters the heat distribution in both the water and the air in each region, forcing a cascade of global climate-related changes.

The interesting finding is that El Niño has been strengthening over the past 5,000 years. This means that its effects on climate are mounting are temperatures warm. That said, better observational data is needed in order to refine the science; more coral samples and sediment measurements from different locations could tell researchers a bit more about what happened in the past in the Central Pacific.

"It's really an open door, we need more data to get a more significant model," said Liu. "With this study, we are providing the first benchmark for the next five, 10, 20 years into the future."

The findings are published in the journal Nature.