Dry January? The Earth went for it and broke yet more heat records

The world set another monthly heat record in January. That may sound like something we’ve heard a lot lately, but this latest record has scientists mystified, surprised and even “terrified.”

January 2025’s data is particularly troubling: despite conditions that should have cooled things down, Earth recorded its hottest January in recorded history.

We’ve been on a run of record-setting temperatures ever since June 2023 when global heating suddenly kicked up a gear. Scientists are still trying to figure out what’s happening — why the last two years were so inexplicably hot and 2024 broke through the symbolic figure of 1.5 degrees above temperatures before the industrial revolution. The worry is that all this fossil fuel burning has unleashed an unexpected step change in the climate system. 

But, whatever else is going on, part of the explanation was that the Earth was in an El Niño phase, when the equatorial Pacific runs hot. And most experts were expecting temperatures to moderate, at least temporarily, as our planet’s weather systems shifted into La Niña. Maybe we’d get back to the regular, old pace of steady, predictable climate breakdown. 

That hasn’t happened. The grand cycles of Gaia have shifted from El Niño to its cooler cousin, La Niña, but January was the hottest January on record: “another surprising month,” said Samantha Burgess, Deputy Director of Europe’s Copernicus Climate Change Service.

In fact, January was 1.75 C above the pre-industrial level, “continuing the record temperatures observed throughout the last two years, despite the development of La Niña conditions in the tropical Pacific and their temporary cooling effect on global temperatures,” Burgess said.

For those of you who are graphically inclined, the dark red dot, up alone on the left shows how last month stands out. 

There is no longer an El Niño boosting global temperatures but the record-setting continues. And, as you can see, January beat the previous record by a sizeable margin, despite La Niña. “This means that January 2025 stands out as anomalous even by the standards of the last two years,” wrote Zeke Hausfather (who memorably described periods of the last two years as “gobsmackingly bananas”).

To visualize just how extraordinary January was, climatologist Brian Bretschneider plotted every January from 1940 up to 2025 (red for Januaries during hot El Niños and blue for Januaries during cooler La Niñas).

The most measured descriptions from climatologists are adjectives like “surprising,” “unexpected” or “anomalous.” Some confess to being “mystified.” Other scientists were using much starker language. Bill McGuire, an emeritus professor at University College London, described it as: “astonishing and frankly terrifying.”

Dr. Friederike Otto, co-founder of World Weather Attribution, thinks we should keep focused on the fundamentals that persist beyond the El Niños and La Niñas: "This January is the hottest on record because countries are still burning huge amounts of oil, gas and coal," she emphasized.

"The Los Angeles wildfires were a stark reminder that we have already reached an incredibly dangerous level of warming.” Otto warns. “We'll see many more unprecedented extreme weather events in 2025.”

The news of January’s unexpected heat record happened to land the same week as James Hansen’s latest salvo. Hansen, you may well know, is the former NASA scientist we should have been listening to since he testified before the U.S. Senate in 1988. 

Along with a team of other researchers, Hansen published a new paper titled with the rhetorical question: Global Warming Has Accelerated: Are the United Nations and the Public Well-Informed? 

The pace of global warming has been underestimated and has accelerated by more than 50 per cent in the last 15 years, according to the analysis by Hansens team. The team expects that 1.5 C is now pretty much the climate’s baseline — not an objective to avoid but a reality to endure. Although there will be natural variation over the next few years, “global temperature will not fall much below +1.5°C level.”

Looking ahead to the next couple of decades, Hansen says the international target of 2 C is “dead” and scenarios that purport to keep global heating below that target are “implausible.”

The recent surge in temperatures shows the climate is more sensitive to carbon loading than most estimates published by the Intergovernmental Panel of Climate Change, according to Hansen’s team. And a major explanation for the recent acceleration is an unmasking of the climate’s true sensitivity by removing aerosol pollution. 

It sounds paradoxical and the researchers call it a “Faustian bargain.” In one example, recent regulations on marine shipping have cut down sulfur pollution from container ships. A worthy effort because of the dangerous health impacts, but those tiny particles in the atmosphere had also been shielding the planet from the sun’s heat. By thinning the shield, we’re beginning to feel more of the actual greenhouse effect from all the carbon dioxide that’s been pumped into the atmosphere. 

“As global pollution control has improved and clean energies are introduced, the cooling effect of aerosols is lost: with the change of ship regulations, our first Faustian payment came due,” write the researchers.

This conclusion has led Hansen to advocate for researching controversial solutions, including Solar Radiation Modification — something we are going to be hearing about more and more, especially if his team’s predictions play out. The research team calls it “purposeful global cooling.”

The idea of Solar Radiation Modification (SRM) has been around for half a century. The basic concept is to mimic the cooling effect of volcanoes by injecting particles high into the stratosphere. 

SRM couldn’t replace the need to cut greenhouse gases from burning fossil fuels and it wouldn’t blunt all impacts of spewing carbon (ocean acidification would continue, for example). But Hansen argues that we may well need it, at least temporarily. SRM may become the most ethical option to limit impacts on the most vulnerable because “Humanmade climate forcings are already geoengineering the planet at an unprecedented, dangerous rate.”

Hansen is now 83 years old and, after a career watching his generation fail to tackle climate change, he worries about the danger of again “being too late” to provide younger generations with information about “purposeful global cooling.” 

“We do not recommend implementing climate interventions,” he writes. “But we suggest that young people not be prohibited from having knowledge of the potential and limitations of purposeful global cooling in their toolbox.”

Hansen’s advice is controversial, and not all climate scientists agree with his findings on the amount of acceleration in global warming. But, as the “surprising” months keep piling on top of “anomalous” ones, his decades-old warnings seem increasingly prophetic.