- January 2025 was the hottest January on record, defying expectations of a cooling trend.
- The persistence of high temperatures has surprised scientists, raising questions about new climate behaviors.
- Human activities, such as burning fossil fuels and deforestation, remain the primary drivers of global warming.
- Additional factors, like reduced air pollution and a strong solar cycle, may be contributing to the heat.
- The unprecedented warming highlights the urgent need for stronger climate action to meet global goals.
January 2025 has officially been declared the hottest January ever recorded globally, according to data released by the National Oceanic and Atmospheric Administration (NOAA). This marks yet another milestone in a worrying trend of record-breaking temperatures, as the planet continues to warm at an alarming rate.
Both 2023 and 2024 shattered previous temperature records, with global temperatures hovering near or above 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels.
However, scientists had anticipated a slight cooling trend in 2025, as the strong El Niño event that contributed to the intense heat of recent years had faded by late 2024. El Niño, a natural climate cycle, often leads to warmer global temperatures, while its counterpart, La Niña, typically brings cooler conditions. Earth transitioned into the La Niña phase last year, but the expected reprieve never materialized.
Instead, January 2025 broke more records. NOAA reported that it was the hottest January in its 176-year history, while the European Union’s Copernicus Climate Change Service noted that temperatures were 1.75 degrees Celsius (3.15 degrees Fahrenheit) above historic levels.
A Persistent Warming Trend
The persistence of record-breaking heat has surprised many climate scientists. Zeke Hausfather, a climate scientist with Berkeley Earth, points out that the dramatic temperature jump that began in mid-2023 has continued unabated. This has led researchers to question whether climate change is pushing Earth’s oceans and atmosphere into new and potentially unforeseen patterns of behavior.
While a hot January doesn’t guarantee that the rest of 2025 will continue to break records, it does increase the likelihood that the year could follow the extraordinary warming trend of the past few years.
Why Is It So Hot?
The primary driver of the recent heat is no mystery, says Samantha Burgess, director of the EU’s Copernicus Climate Change Service. “We’ve burned a lot of fossil fuels, we’ve deforested and urbanized a lot of areas. And this has changed the chemicals in the atmosphere, on the land, and in the ocean,” she explains. These human activities have caused the planet to heat up steadily over time.
However, the progression of global warming isn’t always smooth. While the overall trend is clear, there are periods of slower warming and sudden jumps. The past two years, 2023 and 2024, saw temperatures leap about 0.2 degrees Celsius higher than expected—equivalent to a decade’s worth of warming at current rates. This unexpected surge has left scientists scrambling to understand the underlying causes.
Factors Behind the Heat
One major factor considered was the El Niño phenomenon, which likely contributed significantly to the heat in 2023 and early 2024. However, Hausfather notes that by now, temperatures should have dipped slightly due to the onset of La Niña. This hasn’t happened, suggesting other factors are at play.
A combination of influences may be driving the persistent heat. For instance, a stronger-than-expected solar cycle is pumping extra energy into the atmosphere. Additionally, reduced air pollution from ships and industrial areas in East Asia may be leading to fewer clouds over key ocean regions, allowing more solar heat to be absorbed.
The Bigger Picture: Climate Goals at Risk
The 2015 Paris Agreement set a goal of limiting global warming to well below 2 degrees Celsius (3.6 degrees Fahrenheit), with efforts to keep it under 1.5 degrees Celsius. However, with each passing year of continued fossil fuel emissions, this goal becomes increasingly difficult to achieve. Many countries were required to submit stricter national climate plans by early 2025, but nearly all missed the deadline.
The unprecedented heat of recent years underscores the urgency of addressing climate change. Radley Horton, a climate scientist at Columbia University, warns that the risks of warming may be even more dramatic than previously thought. “Could new physical processes be emerging that climate models are not fully capturing and that human imagination is not very good at preparing for?” he asks.
A Call to Action
The record-breaking temperatures of January 2025 serve as a stark reminder of the accelerating pace of climate change. As scientists continue to study the complex interplay of factors driving global warming, the need for immediate and decisive action to reduce greenhouse gas emissions has never been more critical. The future of the planet depends on it.
