Just over 10 years ago I interviewed Kevin Trenberth in San Francisco, in the midst of what turned out to be a strong El Niño event, when global temperature rose smartly through 2015-16, in a pattern that Dr. Trenberth described as a “step function”, and he hypothesized that successive El Niño events, since they represent a major cycle in ocean absorption and release of heat to the atmosphere, were important markers of the global heating process.
We have enough of a record now to see that Dr Trenberth was broadly correct. The El Niño cycle seems to be an important one in which planetary temperature equilibrates to a somewhat higher level.
The cycles historically recur on a 2 to 7 year cycle, the last one was 2023-24, with 2024 being the warmest year in the record.
This year’s El Niño is looking increasingly likely to have wide-reaching impacts across the planet.
It’s still in its developmental stages and it’s too early to confidently say just how strong it may become, but its tendencies have been similar to major events in the past — boosted by record-breaking westerly wind bursts in the Pacific, which blow warm water eastward.
No two El Niño events are exactly alike, but here are some of the possibilities.
Atlantic hurricane season impacts
Harsh winds in the middle and upper atmosphere during formidable El Niño events can create conditions that are less conducive to hurricane formation.
“Overall, this would be about as unfavorable an Atlantic look as you could get for the peak of hurricane season,” wrote meteorologist Andy Hazelton, who has been tracking this potential El Niño’s impact on the upcoming Atlantic hurricane season, which starts June 1.
Even if there are fewer storms, El Niño doesn’t tell you where hurricanes may go. It only takes one landfall — as demonstrated by Hurricane Andrew in Florida in 1992 — for it to be a memorable season.
The strongest El Niño events almost always cause a record warm year. That’s because heat comes out of the ocean during El Niño, overspreads the tropics in the Pacific, then gets redistributed across the planet.
“The El Nino cometh,” wrote climate scientist Zeke Hausfather.
Continue reading “Up the Temperature Stair Case: Super El Niño Could be a “Major Jump””




