The last decade was the hottest on record, warned the World Meteorological Organization (WMO), a UN agency, in a report released on Monday, March 23. The document highlights that Earth’s climate has never been so out of balance, reinforcing the urgency of action against climate change.
The State of the Global Climate 2025 report was released in conjunction with World Meteorological Day and issues a warning: “The climate of planet Earth is more out of balance than ever.”
Looking at indicators such as greenhouse gas emissions, land and ocean surface temperatures, melting ice, and the Earth’s energy balance, experts point to “rapid and large-scale changes” recorded in recent decades, but which will have negative repercussions for hundreds of years.
According to the most recent data, the period between 2015 and 2025 recorded the highest average temperatures on record, and last year, which ended under the influence of the La Niña phenomenon (associated with lower global temperatures), was one of the hottest, exceeding the pre-industrial average of 1850–1900 by 1.43 °C.
For the first time, the State of the Global Climate report also included the Earth’s energy balance—which measures the rate at which energy enters and leaves the Earth system—as one of the key climate indicators.
In a stable climate, the energy received through solar radiation is equivalent to the energy released, but experts explain that rising concentrations of heat-trapping greenhouse gases have disrupted this balance. The data reveal that the Earth’s energy imbalance “has been steadily increasing since records began in 1960, reaching a new peak in 2025.”
According to the most recent data, the period between 2015 and 2025 saw the highest average temperatures on record, and last year—which ended under the influence of the La Niña phenomenon (associated with lower global temperatures)—was one of the warmest, exceeding the pre-industrial average for 1850–1900 by 1.43 °C.
The overwhelming majority of excess heat (over 91%) is absorbed by the ocean, impacting the ocean’s heat content (down to a depth of 2,000 meters), which has risen steadily over the past nine years and reached a new peak in 2025.
The result is the degradation of marine ecosystems, the loss of biodiversity, the reduction in the ocean’s capacity to absorb carbon, the intensification of tropical and subtropical storms, and the worsening loss of sea ice in the polar regions.
The ocean also absorbed about 29% of the carbon dioxide (CO2) emitted by human activity between 2015 and 2024, impacting the pH of the ocean surface, which has been decreasing over the past 41 years, making the water more acidic.
On the other hand, 3% of the excess energy is responsible for melting, and in 2025, “exceptional losses” of glacial mass were recorded in Iceland and along the Pacific coast of North America, along with record lows in the average annual extent of Arctic sea ice.
Between ocean warming and melting, the average sea level is about 11 centimeters higher than when satellite measurements began in 1993, a trend that, according to projections by the Intergovernmental Panel on Climate Change (IPCC), will continue for centuries, resulting in “irreversible changes also in the pH of deep waters.”
The report also highlights the consequences of climate change on health, particularly regarding mortality, livelihoods, and increased risks such as vector-borne and waterborne diseases or mental health issues.
“And in this era of war, climate stress also reveals another truth: our dependence on fossil fuels is destabilizing both the climate and global security,” added United Nations Secretary-General António Guterres, as quoted in a statement.
Guterres warned that “climate chaos is accelerating, and delay will be fatal. Planet Earth is being pushed beyond its limits.”
Source: Notícias ao Minuto
