Earth experienced its hottest year on record in 2024, with significant temperature increases that caused the planet to briefly exceed a critical climate threshold, according to weather monitoring organizations.
This marks the first time in history that the Earth’s average temperature remained above a desired warming limit throughout an entire year. Measurements from four out of six monitoring teams confirmed this trend, with scientists warning that prolonged warming above this threshold could lead to heightened mortality rates, destruction of habitats, loss of biodiversity, and rising sea levels linked to the intensified weather events that accompany warming.
In addition to this alarming trend, 2024 also witnessed multiple climate disasters in the United States, totaling 27 occurrences that generated over a billion dollars in damages each. As 2025 began, Southern California faced devastating wildfires.
The global average temperature for last year significantly surpassed the previous record set in 2023, crossing the long-term warming threshold of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels, as stipulated by the 2015 Paris climate agreement. This assessment came from various climate organizations, including the European Commission’s Copernicus Climate Service, the UK’s Meteorological Office, Japan’s weather agency, and the privately-operated Berkeley Earth team.
Interestingly, two U.S. government agencies measured last year’s temperature below this 1.5 degree threshold, with the National Oceanic and Atmospheric Administration (NOAA) reporting 1.46 degrees Celsius (2.63 degrees Fahrenheit) and NASA recording 1.47 degrees Celsius (2.65 degrees Fahrenheit). Conversely, the Copernicus Climate Service recorded warming levels at 1.6 degrees Celsius, Japan noted 1.57 degrees, and the British agency reported 1.53 degrees. Berkeley Earth reported the highest figure at 1.62 degrees Celsius.
Disparities among the estimates are minimal and largely arise from the methods used to measure ocean temperatures. The World Meteorological Organization synthesized these figures to arrive at a composite warming of around 1.55 degrees Celsius, a figure deemed a “reasonable assessment” by NASA climate scientist Gavin Schmidt.
Samantha Burgess, a strategic climate lead at Copernicus, attributed these record temperatures primarily to the accumulation of greenhouse gases resulting from fossil fuel combustion. She emphasized that as these greenhouse gases persist in the atmosphere, temperatures continue to rise, contributing to increases in ocean temperatures, rising sea levels, and the melting of ice sheets and glaciers.
According to NOAA, the year was not just the hottest in the United States since record-keeping began in 1850, but it was also potentially the hottest globally in around 125,000 years. NOAA monitoring chief Russ Vose remarked that the trend is likely to persist, stating, “when there’s more heat in the system, it has cascading effects on other parts of the environment.” He elaborated that rising sea levels and the greater moisture capacity of warmer air lead to more extreme weather events.
Fossil fuel combustion remains the principal driver of these record temperature increases, with several scientists noting that the El Niño phenomenon that started the year likely added about a tenth of a degree Celsius to the year’s overall temperature readings.
Alarm signals regarding climate change have continued to sound, leading some experts to fear a growing desensitization to the urgency of the situation. Jennifer Francis from Woodwell Climate Research Center commented that despite public fatigue, the call for action is becoming increasingly pressing.
Marshall Shepherd, a professor at the University of Georgia, compared the situation to a car dashboard warning light, highlighting incidents like Hurricane Helene, catastrophic floods in Spain, and severe wildfires in California as indications of a concerning climate shift.
In the U.S. alone, the NOAA reported 27 severe weather-related disasters costing over $1 billion each, nearing the previous year’s record. The financial toll of these disasters reached $182.7 billion, with Hurricane Helene being both the deadliest and costliest, claiming at least 219 lives and causing approximately $79.6 billion in damages.
Katharine Hayhoe, a climate scientist at Texas Tech, pointed out that in the 1980s, the average frequency of billion-dollar weather disasters in America was once every four months. Today, it has intensified to approximately once every three weeks, and the year began with the first of many disasters already recorded in 2025.
Experts clarified that the 1.5-degree Celsius target is meant for long-term warming averages, currently defined as a 20-year mean. The long-term temperature rise from pre-industrial times now stands at 1.3 degrees Celsius (2.3 degrees Fahrenheit). Victor Gensini, a climate scientist from Northern Illinois University, emphasized that breaching this threshold—even for just one year—raises serious concerns about the sustainability of the planet’s climate, a view echoed by research indicating that maintaining temperatures below this limit could preserve vital ecosystems like coral reefs and mitigate the impacts of climate change on human life.
Looking ahead, scientists predict that with the transition from an El Niño to a cooling La Niña, 2025 may not be as warm as 2024 but could still be among the hottest years recorded. Preliminary data shows that despite cooler temperatures in parts of the U.S., early January 2025 was warmer than the historical averages for this time of year.
There remain differences of opinion among scientists about whether global warming is accelerating. Carlo Buontempo, director of Copernicus, noted that while atmospheric warming shows little acceleration, ocean heat content appears to rise more rapidly.
Commenting on the current situation, Michael Mann, a climate scientist at the University of Pennsylvania, likened it to the storyline of a dystopian science fiction film, stating, “We are now reaping what we’ve sown.”
Planet sets new annual temperature record, exceeding critical warming limit
