In Short : The description suggests that the severe El Niño event in South America is seen as a glimpse into what the world might experience in a climate-changed future. El Niño events, characterized by abnormal warming of sea surface temperatures in the Pacific Ocean, can lead to extreme weather conditions globally, including droughts, floods, and disruptions to ecosystems. Associating this event with climate change emphasizes the potential for more intense and frequent extreme weather events as the climate continues to change.
In Detail : Dengue, drought, and floods are hammering Peru and Bolivia this year. At the UN climate talks, they’re seeking justice.
For centuries, off the coast of what’s now Peru and Ecuador, fishers noticed that every few years, around Christmas, the sea surface warmed up.
Ordinarily, a chilly swirl of currents would churn up nutrients that feed wildlife near the surface, yielding a bountiful catch. The arrival of warm water slowed the currents, and thus halting the upwelling of phosphorus and nitrogen from deep in the ocean that normally fed plankton that in turn fed fish. As a result, the fishermen would often return home with empty nets.
Spanish settlers later dubbed this phenomenon “El Niño,” the boy, a reference to the Christmastime birth of Jesus.
Since then, scientists have learned that what fishers observed is actually a powerful mechanism that ripples all the way across the Pacific Ocean and reshapes weather around the world. And as average temperatures have risen thanks to human-caused climate change, they’ve amplified El Niño’s disruption.
This year, the combination of a powerful El Niño and record-high levels of carbon dioxide in the atmosphere has warmed the planet to the hottest levels humans have ever measured.
It may also be the first time global average temperatures rise 1.5 degrees Celsius, 2.7 degrees Fahrenheit, above average temperatures before the Industrial Revolution and all the fossil fuel burning that ensued. The 2015 Paris climate agreement set a goal of holding average temperature increases to less than 1.5°C. A single year rising above this line doesn’t mean that the average has shifted yet, but it provides an example of what the world will look like when an extreme year like 2023 becomes typical.
While El Niño is a phenomenon independent of climate change, its increasing ferocity has created a preview of life on the planet as temperatures continue to rise. “The impacts of El Niño look a lot like what the impacts of climate change are going to be,” said Christopher Callahan, an earth science researcher at Stanford University.
Some of El Niño’s most acute consequences are in the places closest to where it was first documented. The Andean region, a towering mountain ridge running down South America’s Pacific coast, forms a microcosm of the planet as a whole, from its beaches to its peaks, its deserts to its rainforests. During El Niño years, countries like Colombia, Ecuador, Peru, and Bolivia — together home to more than 110 million people — suffer from strengthened heat waves, drought, and heavy rains. And this year is already leaving scars.
The region has experienced an unusually warm Southern Hemisphere winter with intense heat waves that left inland lakes near record-low water levels. That’s on top of six decades and counting of glacier retreat in the Andes mountains, threatening the long-term water supply for countries like Peru. The Andean region has also seen heavy rains and deadly floods in 2023. The severe weather has damaged farms and is accelerating a migration from rural to urban areas in several South American countries. Now summer is setting in, and more weather extremes are looming.
The current El Niño is poised to be costly. Peru’s government is expecting to spend more than $1 billion to cope with the extremes this year stemming from the severe weather this year and ongoing climate change impacts — a huge sum for a country with a gross domestic product of $242 billion, nearly a hundred times smaller than that of the US. At the United Nations, Peruvian President Dina Boluarte this year proposed creating a new international pact just to deal with El Niño’s devastation.
Now negotiators from the Andean region are meeting their counterparts from around the world at COP28, the annual United Nations climate summit, held in the United Arab Emirates this year, to hash out the next steps for action on climate change. One of the highest priorities for countries like Peru and Ecuador is to secure more funding to cope with the climate change damage underway, as well as the greater toll that lies ahead. The United Nations this year estimated that it will cost about $387 billion per year for developing countries to adapt to climate change. It’s a tough ask at a time when many countries, rich and poor, are reeling from their own economic woes.
Yet the goal of keeping warming below 1.5°C on average is almost out of reach, and global greenhouse gas emissions are still rising. “We’re getting closer and closer to the point where we are not going to meet our targets,” said Shaun Martin, vice president for climate change adaptation at World Wildlife Fund US.
Like El Niño itself, the Andean region faces some of the most severe consequences from climate change, but the hardships for its people and economies will reverberate across the globe.
How climate change and El Niño are converging in South America this year
Hot water at the surface of the Pacific Ocean during an El Niño year ripples below the sea and into the sky, as warm water leads to more evaporation, which in turn causes more rainfall. In South America, the Andes mountains channel that moisture so that some areas get a lot more precipitation, while others get much less. But subregions like the Peruvian Andes can experience both extremes in a season, a brutal whiplash from floods to drought, making it extraordinarily difficult for residents to adapt.
“It’s hitting both sides of the Andes, in the Amazon and on the coast,” Martin said. The Amazon river, which has its source in Peru, is suffering from a severe drought this year. Alongside extreme heat, the weather has contributed to wildlife deaths, including dozens of Amazon river dolphins. The dry weather also left the Pantanal wetlands just south of the Amazon rainforest primed to burn. Fires ignited by lightning charred critical wetlands for jaguars.
South America’s Pacific coast, meanwhile, is poised to receive intense rain as well as more flooding from high tides through the end of the year. The high water levels are likely to wash out roads, bridges, and other pieces of low-lying infrastructure. And in the coming years, rising average temperatures will continue to amplify these extremes.
For people living in Peru, Bolivia, Ecuador, and Colombia, this year’s El Niño is occurring on top of years of shifting temperature and precipitation baselines. And the effects of severe heat and drought are particularly strong on children. “They are affected in going to school because of the high temperatures. Sometimes they have to walk many hours to reach their school,” said Marianela Montes de Oca, country director for Save the Children in Bolivia. “It’s starting to affect children with gastrointestinal infections because of the lack of water.” As wells, ponds, and cisterns dry out, children can end up drinking from contaminated sources.
These changes are making it harder for subsistence farmers to survive as losses mount due to weather extremes, leading many to move away from rural areas toward cities. In countries like Bolivia, that migration presents social challenges. Much of the rural population is Indigenous and speaks languages like Quechua or Aymara, so it’s harder for them to integrate in cities where Spanish is far more common, limiting access to jobs, housing, and health care.
Bolivia has been a bright spot in global development, growing its economy and making advances in key development indicators like reducing infant mortality and poverty. Bolivia has an extreme poverty rate of 11.1 percent based on the most recent assessments from the World Bank. The Bolivian government set a goal of ending it entirely by 2025. But according to the United Nations World Food Programme, climate change is threatening to undo some of this progress. Unless the pace of warming decreases, Bolivia is poised to see a 22 percent increase in food insecurity by the 2050s. This year’s El Niño provides a stark example of conditions that could become more frequent as record-breaking temperatures triggered drought emergency declarations across 20 percent of the country, threatening thousands of acres of farmland.
Peru has also been getting hammered by extreme weather this year. Heavy rains since January killed at least 77 people, made almost 50,000 homes uninhabitable, and left more than 800,000 people in need of government assistance, about 30 percent of them children. Cyclone Yaku in March triggered floods and mudslides, wiping out the entire rice crop for some farmers.
The weather this year is also harming public health, even in areas that didn’t directly experience torrential downpours or searing temperatures. Because of their altitude, most major Peruvian cities have historically had very few mosquitos. But with rising temperatures and changing rainfall patterns, mosquitos are climbing further up, and so are the diseases they carry. “El Niño always comes associated with dengue outbreaks,” said Melissa Allemant Salas, humanitarian response leader for Save the Children Peru.
The spread of dengue in Peru has now exceeded the outbreak in 2017, during the last big El Niño. According to the Pan American Health Organization, the Andean region as a whole has seen 550,000 cases of dengue and 640 deaths from the infection this year. Peru accounts for more than 270,000 cases and 448 deaths, including 47 children — an “outrageous number,” Allemant Salas said, for a disease that under normal conditions should be easily controllable.
This all adds up to a tremendous economic toll. Stanford’s Callahan co-authored a study in the journal Science this year looking at the dollar values of damages from past El Niño events. The El Niño in 1997-98, one of the most severe on record prior to 2023, led to $5.7 trillion in income losses around the world. But the toll was concentrated in tropical countries like Peru that experienced the biggest weather perturbations. Five years after that El Niño, economic growth in Peru declined by 6.2 percentage points. The income for the average Peruvian would have been $1,246 greater in 2003 had the 1997-98 El Niño not occurred, the authors calculated.