With El Niño expected to stretch into the winter, all eyes are on 2024

There is little doubt among climate forecasters that 2023 is on track to beat out 2016 as the warmest year on record globally.

As we keep pumping greenhouse gases into the atmosphere, our planet continues to warm. But this year has seen a confluence of events that appear to be pushing temperatures even higher than expected.

One of those events is an El Niño, a natural and cyclical warming in the Pacific Ocean that warms the atmosphere above it, which can raise the global temperature and alter weather patterns across the planet. 

But experts say that so far, it's played a small part in 2023's soaring temperatures. Its bigger role is yet to come.

"Usually, it's the subsequent year that is the warmest year," said Tom Di Liberto, a climate scientist and public affairs specialist at the National Oceanic and Atmospheric Administration (NOAA).

"El Niño normally peaks around this time of year, the beginning of the new year, and then usually ends sometime in the springtime…. We'll see if that holds true."

For the NOAA to declare an El Niño, a specific part of the Pacific Ocean called Niño 3.4 must be 0.5 C warmer than the seasonal average for three consecutive months, with the expectation that it will continue for five consecutive three-month periods.

This year, the first three-month period occurred from April to June. The fifth will be the August-to-October period. (The monthly diagnostic report will be issued the second week of November.)

However, no two El Niños are ever the same, and sometimes temperatures in the region can reach an increase of 1.5 C or higher, which is considered "strong." 

And this seems to be the path we're on.

"I think, generally speaking, the chances of this event being a strong event is about 75 to 85 per cent," Di Liberto said. 

He added that when an El Niño is stronger, it doesn't mean that impacts will be stronger. Rather, we will see impacts most associated with these events — one of which is a potential jump in global temperatures in 2024.

The last strong El Niño occurred in 2015-16. Ocean temperatures began to surge above 1.5 C warmer than average in the summer of 2015 — eventually reaching as high as 2.6 C — but it was the following year that broke global temperature records.

So if this year is on track to be the hottest yet, and the pattern holds, could 2024 be even hotter?