The record heat in the world has lasted 14 months. When will it end?

Since the most recent El Niño ended in May, the tropical Pacific has resided in a neutral state – neither El Niño nor La Niña is occurring.

But human-caused climate change is steadily increasing heat (SN: 7/13/23). “There is some variability from year to year, but overall we see an increase in temperatures since the mid-1970s,” says climatologist Karin Gleason of NOAA’s National Center for Environmental Information in Asheville, NC. : When El Niño arrives, we jump a few notches; when La Niña comes, we pull back a bit – but we’re still higher than when we got on.

Amidst all this constant heat, Scientific news spoke with Gleason to learn more about the ongoing global heatwave. The following conversation has been edited for length and clarity.

SN: When will this current hot streak end?

Gleason: A La Niña is predicted for this fall, so we’re rolling. We are moving from a warming signal to a cooling one. Depending on how quickly and intensely this happens, we expect the generation to end sometime this year, possibly sometime in the next few months. July 2024 was only three hundredths of a degree Celsius warmer than the previous July. You could almost call it a picture finish. Knowing that margin was so close, we don’t know what’s going to happen in August at this point.

SN: El Niño ended in May, so why did the hot streak continue?

Gleason: There is a lag time between things starting to calm down and our planet reacting.

SN: Besides its longevity, what distinguishes the ongoing hot streak from others in the past?

Gleason: In talking to other people in the climate science community, I think there has been some advice. It was surprising how quickly the warmth intensified at the end of last summer, going into autumn. And I don’t think anyone predicted the persistence and extent of the record warm waters of the Atlantic Ocean (SN: 15.6.23).

SN: When might the next hot streak appear?

Gleason: Assuming the temperature trend continues to rise, we will have a strong El Niño next time [the timing of which is hard to predict]it’s very likely that we could go back to having several consecutive months that are in record territory for the globe. Whether or not it will surpass this streak, whenever it ends, remains to be seen.

SN: Here’s a question from Scientific news reader Dorothy Hunt on climate change: Have we passed the point of no return?

Gleason: I don’t know if there’s necessarily a magic temperature we have to stay below. I think the take home message is that … anything that everyone does collectively can have an impact. The higher we go, the harder it is to break down, so every little bit now counts and will help in the future.

Please keep sending in your questions about Earth’s extreme heat and climate change—we’ll be looking for questions to answer in future Extreme Climate Update columns.