El Nino slows economy for years, costs trillions: Report

El Nino describes the warming of surface waters in the eastern Pacific Ocean that alters air and water currents worldwide.

Researchers at the United States' Dartmouth College looked at global economic activity in the decades following the 1982-83 and 1997-98 El Nino events, and found a "persistent signature" of slowed economic growth more than five years later.

The study, published in the journal Science, found the global economy bled US$4.1 trillion and US$5.7 trillion in the half-decade after each of the events, most of it borne by the world's poorest nations in the tropics.

Researchers Justin Mankin and Christopher Callahan project that global economic losses for the 21st Century will amount to US$84 trillion as climate change potentially amplifies the frequency and strength of El Nino.

The El Nino predicted for 2023 could hold the global economy back by as much as US$3 trillion by 2029, they said.

"We can say with certainty that societies and economies absolutely do not just take a hit and recover," Callahan said.

"In the tropics and places that experience the effects of El Nino, you get a persistent signature during which growth is delayed for at least five years," he said.

The estimated cost of global warming had to include the impact of El Nino, Mankin said.

"Our welfare is affected by our global economy, and our global economy is tied to the climate," he said.

"El Nino amplifies the wider inequities in climate change, disproportionately impacting the least resilient and prepared among us."

El Nino usually brings severe drought in Australia, parts of Africa and South America, and heavy rainfall along the US Pacific coast.