El Nino in the Pacific sets daily warm water records. Scientists say the world is in uncharted waters and we don’t know what will happen next.
Can scientists still really trust El Niño forecasts?
Scientists have warned that while El Niño reduces the likelihood of hurricanes, storms can still form because the ocean stores excess heat.
The world’s most influential climate pattern is bearing its fangs in the Pacific Ocean.
The strengthening of El Niño, the natural warming of ocean waters that affects weather around the planet, is setting daily warm water records.
“Not only is it very likely to be the strongest event since reliable records began, it may be the strongest by a truly astonishing margin,” Berkeley Earth research scientist Zeke Hausfather wrote in a post on Substack’s Climate Brink in early July.
It remains to be seen how this will affect global weather over the next 12 to 18 months, but climate scientists say El Niño’s impact on global temperatures will increase the likelihood that 2026 will be the warmest year on record, and 2027 will likely be the warmest.
Meanwhile, world leaders have expressed concern about the prospect of droughts, heavy rains and heatwaves. (It’s worth noting, however, that not all El Niño effects are brutal; this weather pattern is widely expected to moderate the 2026 Atlantic hurricane season.)
The effects of El Niño are already being felt in the United States, with Atlantic hurricane activity being suppressed and bringing extreme heat and humidity to parts of California, one of the states most susceptible to El Niño.
Hausfather and Berkeley Earth colleague Robert Rohde said in their monthly climate briefing on July 23 that sea surface temperatures have already exceeded the threshold for a very strong event.
The upward trajectory of sea surface temperatures in the El Niño region along the equator is “significant” and is moving faster than the 1997-1998 El Niño, Hausfather wrote in an earlier post.
Water temperatures in the region have never been this hot in July in recent records, according to NOAA data.
Why scientists are concerned
El Niño is a naturally occurring pattern, but when combined with warmer-than-normal temperatures around the world due to climate change, there are growing concerns that its effects will be amplified.
Daniel Swain, a climate scientist at the University of California’s College of Agriculture and Natural Resources, said the world is watching the “unprecedented combination” of a strong El Niño and warming temperatures due to climate change. That will impact what El Niño actually means on the ground in the U.S. and around the world, Swain said.
Previous El Niño events temporarily raised global temperatures by about 0.54 degrees Fahrenheit, he said. Currently, the Earth is experiencing the effects of long-term human-induced warming, and further warming is expected to occur on top of this.
“El Niño is a pretty big problem to begin with, with potentially record-breaking temperatures on top of record-breaking global temperatures,” he said.
“It is likely that we will set a new warm record for average global temperatures this year, next year, or both,” Swain said. “If we don’t make it this year, we can almost certainly do it next year.”
Sea surface temperatures in the Pacific’s El Niño region were up to 6 degrees warmer than normal on this day, an event that is several times more likely to be caused by climate change, according to Climate Central, a nonprofit climate science and communications organization.
“The most surprising thing is how powerful this event is expected to be,” Hausfather and Rohde said at a news conference. The researchers concluded that the majority of computer models predict an El Niño that will exceed the record-breaking event of 2015-2016, even when accounting for background ocean warming. “This is likely to be the strongest El Niño ever observed.”
What can be expected from the effects of El Niño?
A “very strong” El Niño could affect weather around the world.
“El Niño will further increase global temperatures,” said Alvaro Silva, a scientist at the World Meteorological Organization. “We know that in El Niño years, global temperatures typically reach record levels.”
A strong El Niño in the United States means “a pretty strong increase in the jet stream,” Swain said. “As a result, winter storms could become more intense and more frequent across California, the interior Southwest, and the southern part of the state.”
“Some of California’s wettest winters have occurred during the strongest El Niño events,” he said.
El Niño can increase hurricane activity in the eastern Pacific Ocean and suppress hurricane activity in the Atlantic Ocean.
Because El Niño affects the water cycle, it can cause catastrophic flooding in some areas, while severe droughts and wildfires can occur in others. It could also disrupt fishing and food production, resulting in trillions of dollars in economic losses.
“Current projections suggest this could be the most damaging El Niño on record,” Justin Mankin, a Dartmouth associate professor of geography who studies El Niño’s economic impact, recently told USA TODAY in an email.
Specifically, the United Nations said that in addition to the Americas, Central America and the Caribbean are likely to experience drier-than-normal conditions. Dry weather patterns are also expected during the monsoon season in Indonesia and parts of Southeast Asia, while wetter weather is expected in East Africa during the rainy season from September to December.
El Niño predictions remain uncertain
Even if signals and models show a strong El Niño, that doesn’t mean it will definitely be the strongest on record when it is expected to peak later this year, said climate scientist Michael Mann, director of the Penn Center for Science, Sustainability, and Media at the University of Pennsylvania.
“It’s clear that we’re heading towards a historically strong event, but there are still many different scenarios possible,” Mann said.
El Niño is an inherently chaotic event in the climate system that does not necessarily respond in a simple and proportional manner, Mann explained. Its biggest impacts come from connections with the larger atmosphere, such as trade winds and upper-atmospheric winds, but those remote connections can be difficult to predict.
Slight differences in conditions such as sea temperature or trade winds can change what happens later. For example, the ultimate impact of El Niño depends on factors such as where the greatest heating occurs near the equator in the Pacific during fall and early winter.
Part of the uncertainty lies in the fact that the model is in “uncharted waters,” Hausfather wrote. The model “has never been tested in this region.”
Swain said such agreement between the strongest predictive models is unusual, but what it means remains to be seen. “Every event has a different flavor, and this one will definitely be unlike anything we’ve seen before.”
Dinah Boyles Pulver and Doyle Rice are national correspondents for USA TODAY and have decades of experience writing about weather and climate. Please contact dpulver@usatoday.com and drice@usatoday.com..
