Attribution teams credit climate change with more of Hurricane Polo's strength than El Niño
World Weather Attribution and Climate Central estimate climate change added about 6 mph to Hurricane Polo's winds, against about 5 mph from El Niño. The comparison covers warm water only and is not yet peer reviewed.
The Scientist · Science desk
Bar chart: climate change made the conditions that fueled Hurricane Polo 23 times more likely, and El Niño made them 14 times more likely, the study found.
How many times more likely each made the conditions that fueled Polo In times more likely
| Item | Value | Claim |
|---|---|---|
| Climate change | 23 times more likely | 3 |
| El Niño | 14 times more likely | 3 |
What happened
- The study found climate change made the conditions behind Polo 23 times more likely, and El Niño made them 14 times more likely.
- Those conditions were 88-degree Fahrenheit waters, as much as 3.6 degrees Fahrenheit warmer than normal, the study said.
- Polo spent two and a half days at Category 5, the longest on record for the Pacific.
- The storm went from tropical storm to Category 5 hurricane in about 24 hours.
- Both teams measured climate change's effect by comparing the real world with a hypothetical one that had not warmed 1.4 degrees Celsius since pre-industrial times.
Why it matters
- constraint The 6-versus-5 comparison ranks the two factors on ocean heat alone, out of everything each did to Polo.
- precedent Otto argues the climate signal outlasts this El Niño, so each future East Pacific hurricane would start with at least this added strength.
- cost The researchers say each extra bit of wind speed can raise damage sharply, but Polo weakened before reaching sparsely populated Mexico, so it did not test that.
The two wind figures differ by about 1 mph [20], and each is reported as "about" a number. The odds ratios sit further apart: 23 against 14 is a factor of roughly 1.6 [21]. In our view the direction of the ranking is better supported than its size. The two research teams measured conditions slightly differently and used different techniques, and they reached the same general conclusion [11].
What they measured matters. The study examined the ocean heat that powers storms, gauged by how intense a storm could potentially become [9]. It did not focus on upper-level wind shear, where El Niño has a large footprint [19]. In the Atlantic, El Niño usually increases those storm-decapitating winds. In the Pacific, because of changes in wind patterns, it decreases them [10].
The study did not estimate how much that second route added to Polo, so it cannot say whether 5 mph is the whole of El Niño's contribution.
Daniel Gilford, a Climate Central scientist and study co-author, offered a traffic picture. Wind shear from El Niño can be a red light, as in the Atlantic, or a green light, as in the Pacific. The extra ocean heat from climate change and El Niño together, in his picture, is a driver with the pedal pushed to the floor [16].
Friederike Otto, who coordinates World Weather Attribution, put the headline result this way: "El Niño and climate change both made this hurricane stronger than it would have otherwise been, but the effect of climate change is even bigger than the one of El Niño," she said [13]. Kristina Dahl, vice president of science at Climate Central, one of the two groups that published the study, said "It's a powerful reminder that even though El Niño right now is shifting hazards around the globe and changing where it's flooding and getting dry, the really dominant signal behind all of this remains climate change" [15].
An outside scientist was less certain at first. Brian Tang of the University at Albany, who was not part of the study, said he was initially surprised, "given how extreme this El Niño is, but from a long-term standpoint, perhaps the result isn't as surprising as it might seem" [17].
Even with neither climate change nor El Niño in play, the researchers also found, Polo would still have been a huge storm [8].
What to watch
- A peer-reviewed version of the analysis, ideally with uncertainty ranges on the 6 mph and 5 mph figures.
- Any analysis that adds El Niño's effect on wind shear in the East Pacific, which would show whether the ranking holds.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence55
- Adoption
- Insufficient
- Hype gap+10
- Incentives
- Insufficient
- Confidence58
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
A joint study published Thursday by World Weather Attribution and Climate Central found that global warming from burning coal, oil and gas added about 6 mph (nearly 10 kph) to Hurricane Polo's strength.
- [2]
El Niño contributed about 5 mph (8 kph) to Polo's strength, a study co-author said.
- [3]
Climate change made the conditions that fueled Polo 23 times more likely, while El Niño made them 14 times more likely, the study found.
- [4]
The conditions involved 88-degree Fahrenheit (31.2 degrees Celsius) waters that were as much as 3.6 degrees Fahrenheit (2 degrees Celsius) warmer than normal, the study said.
- [5]
Polo set the Pacific record for time spent at Category 5, at two-and-a-half days, making it the longest-lasting Category 5 storm in the Pacific.
- [6]
Polo intensified from a tropical storm to a Category 5 hurricane in about 24 hours.
- [7]
Polo weakened considerably before it hit a sparsely populated part of Mexico.
- [8]
Researchers found that without climate change and El Niño, Polo would have been a monster storm anyway.
- [9]
The study looked at the warm water that fuels storms, using a measure of how strong storms can get.
- [10]
El Niño usually increases storm-decapitating high-altitude winds (wind shear) in the Atlantic, but in the Pacific, because of changes in wind patterns, it decreases the winds that weaken storms.
- [11]
The two sets of researchers measured conditions slightly differently and used different techniques but reached the same general conclusion; the rapid study has not been peer-reviewed.
- [12]
To calculate climate change's effect on Polo, both teams compared the warmer real world with a hypothetical world that has not warmed by 1.4 degrees Celsius (2.5 degrees) since pre-industrial times.
- [13]
"El Niño and climate change both made this hurricane stronger than it would have otherwise been, but the effect of climate change is even bigger than the one of El Niño," said Friederike Otto, a climate scientist, study co-author and coordinator of World Weather Attribution.
- [14]
Otto said El Niño comes and goes but climate change only gets worse, so every East Pacific hurricane from now on has at least this climate change signal making it stronger, and that signal will grow as long as fossil fuels are burned.
- [15]
"It's a powerful reminder that even though El Niño right now is shifting hazards around the globe and changing where it's flooding and getting dry, the really dominant signal behind all of this remains climate change," said Kristina Dahl, vice president of science at Climate Central.
- [16]
Study co-author Daniel Gilford of Climate Central likened the process to cars on a road: El Niño wind shear can be a red light, as in the Atlantic, or a green light, as in the Pacific, and water warmed by both climate change and El Niño acts like a driver flooring the accelerator.
- [17]
Brian Tang of the University at Albany, who was not part of the study, said he was initially surprised the research found climate change the bigger influence on Polo, "given how extreme this El Niño is, but from a long-term standpoint, perhaps the result isn't as surprising as it might seem."
- [18]
Every bit of additional wind speed can dramatically increase the damage a hurricane does.
- [19]
The study did not focus on upper-level wind shear, where El Niño has a huge footprint.
- [20]
The gap between the climate change and El Niño wind contributions is about 1 mph.
- [21]
The climate change odds multiplier is roughly 1.6 times the El Niño odds multiplier.
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Sources
1 independent publisher whose own reporting we read for this story.
- Study says global warming did more than El Niño to turbocharge Hurricane Polo | Washington | winchesterstar.com
winchesterstar.com
1 article · October 14, 2026
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