The arrival of an El Niño weather pattern, expected this year, can unleash devastating storms, droughts, floods and wildfires that have far-reaching economic impacts.
El Niño occurs when sea surface temperatures in the tropical eastern Pacific rise by at least 0.5°C above the long-term average, a state that triggers changes in weather patterns around the world, particularly in some places .
For example, it will often bring stronger storms and more flooding in Peru and Ecuador, while in Indonesia and Australia it tends to trigger droughts, wildfires, and coral reef bleaching.
The financial impacts on the hardest-hit nations may be severe and long-lasting, according to a new analysis.
christopher callahan at Dartmouth College in New Hampshire and colleagues analyzed GDP data from 1960 to 2019 for 147 countries to identify the economic impact of El Niño.
They found that it leads to significant carryover up to five years after the event. For example, the 1982-83 El Niño cost the world economy $4.1 trillion and the 1997-98 El Niño cost the world economy $5.7 trillion. Most of this was borne by the poorer nations in the tropics, where the impacts of El Niño tend to be felt most strongly.
“El Niño is really costly and has economic implications that are much larger than previously thought,” Callahan says. “[These events] produce persistent reductions in economic growth that go beyond a simple problem from which countries recover immediately.
The study is the first to suggest a severe and long-term financial impact of El Niño. In 2017, the investigation of kamiar mohaddes at Cambridge University and colleagues suggested that El Niño patterns may cause a short-lived economic shock to some countries, but may have a positive economic impact elsewhere.
In the US, for example, extra rains in California can spur hydroelectric power generation and boost farm yields, while on the US East Coast, milder temperatures can lower utility bills. home heating, which stimulates retail and leisure spending.
Mohaddes is skeptical that El Niño events will have as severe and lasting global economic impact as this latest study suggests. “Actually, on a net basis, El Niño is positive for the world economy,” he says.
“Absolutely, there are some countries that are negatively affected by an El Niño event. But there are also plenty of countries that are not affected by the El Niño effect. And then there are the countries that are positively affected by El Niño,” says Mohaddes.
Callahan says his results are not inconsistent with previous findings, but emphasizes that the new research looked at country rather than regional data and looked at impacts over a long period. “Our numbers are larger and arguably a more accurate accounting of [El Niño’s] costs than theirs,” he says.
justin manwho also worked on the study at Dartmouth College, says: “I think it’s pretty clear, from a purely geophysical standpoint, that El Niño spells disaster for many regions of the world, particularly regions of the tropics that are also low -income and less resilient to climate hazards.
Forecasters expect El Niño conditions to return later this year, with fears growing that the event could prove strong with especially high sea surface temperatures in the Pacific. This would have a significant impact on both global average temperatures and weather patterns around the world.
Better forecasting and preparation for El Niño would increase countries’ ability to cope, Mankin says. But climate change is amplifying the impacts of El Niño by increasing the rate of global warming, she adds, making emissions reductions a priority.
“What these results reveal is that we are really maladapted to the climate that we have and when it happens that El Niño and global warming align, their tendency is to simply amplify the impacts of one another,” he says. “Any preparation we can do on the adaptive side is absolutely essential, but in no way dismisses the importance of climate mitigation as the primary means of preventing further damage.”
