The Club PUBlication 01/13/2025

2024 was the hottest year on record:
Get ready for more
A cooling La Niña could offset temps, but it’s likely to be short-lived.
By CHICO HARLAN, SCOTT DANCE and BEN NOLL The Washington Post

A volunteer pours water over a mans head in an attempt to cool him off during a hot day earlier in 2024 in Karachi, Pakistan.

​This is a climate era when even the most ferocious records are bound to be broken.
​
Scientists in Europe on Friday confirmed that 2024 had been the hottest year on record — and the first to surpass a dangerous warming threshold of 1.5 degrees Celsius (2.7 degrees Fahrenheit) that nations had pledged not to cross.

But even as experts described the year as unprecedented, they acknowledged that it would ultimately become just one more marker in an upward warming trajectory causing havoc on a growing scale.

"As long as people keep burning fossil fuels, this will only get worse," said Friederike Otto, who leads a scientific group, World Weather Attribution, that assesses the role of climate change in amplifying extreme weather events.

In 2024, according to data from the European Union's Copernicus Climate Change Service, temperatures reached 1.6 degrees Celsius above preindustrial levels. Aside from Australia and Antarctica, every continent experienced its warmest year on record. So too did sizable parts of the ocean.

It is the second consecutive year in which the world has set a temperature record. In 2023, the arrival of El Nino — a natural phenomenon that is known to boost global temperatures — brought a jolt of warming much earlier than scientists had expected, with a temperature 1.48 degrees Celsius above preindustrial levels. Then in 2024, temperatures predictably remained elevated in the wake of the fading El Ni'no, and scientists are debating what other factors may have contributed to the margin of record warmth.

Projections suggest that 2025 might not be as hot as the past two years but that it will probably rank in the top five warmest years on record. Despite the year-to-year fluctuations, the general trend is obvious, as is the cause: the emission of greenhouse gases, primarily from fossil fuels. Each of humanity's 10 hottest years have come over the past decade. At the time, 2016 was seen as an unprecedented scorcher — what one climate scientist called a "wake-up call." Just nine years later, 2016 is now looking "decidedly cool," said Adam Scaife, the head of long-range prediction at Britain's Met Office.

In 2024, so many heat-related events caused death and damage that it was hard to keep up.

It was a year in which an estimated 1,300 religious pilgrims died under 120-degree Saudi Arabian heat. It was a year when a smoke plume stretched diagonally across nearly all of wildfire-stricken South America, when heat-exhausted howler monkeys fell dead out of trees in Mexico, and when the hottest place on Earth — California's Death Valley — registered its hottest month ever.

Will the heat continue?
Though the world broke the 1.5-degree Celsius threshold in 2024, that doesn't mean the planet has formally breached the most ambitious target set in the Paris agreement. It will take a much longer span for scientists to make that determination.

Right now, cool water in the equatorial Pacific signals that La Niña has developed. But it is expected to be short-lived.

New climate model projections show the cool water in the Pacific eroding and giving way to warmer-than-average seas by the middle part of 2025.

Meanwhile, warmer-than-average seas are predicted to continue planet wide. This suggests that the planet will have little, if any, reprieve from record warmth in the months ahead.