According to Copernicus experts, 2025 will almost certainly be the second warmest year ever. But there were also months of record-breaking disasters.
2025 is almost certainly destined to go down in history as the second or third warmest year ever. The conclusion of the scientists of the Copernicus Earth monitoring program in their November bulletin leaves little doubt about the trend in global temperatures: for the first time, the averages recorded over three years, from 2023 to 2025, will exceed the +1.5 °C set as the limit threshold by the Paris Agreement.
But the 12 months that are about to end have also marked other extremes, not just on the thermometer. 2025 was a year of disastrous climate events and a dangerous approach to so-called climate tipping points, at least one of which has already been reached.
High temperatures, no longer the “excuse” of El Niño
According to findings from the Copernicus Climate Change Service (C3S), from January to November 2025 the average global temperature was 1.48 °C higher than pre-industrial levels, an anomaly practically identical to that recorded in 2023, the second warmest year on record. The first was 2024, which ended at +1.6°C from the pre-industrial era.
However, the effect of El Niño, the “warm” phase of a periodic climate phenomenon called El Niño-Southern Oscillation (ENSO) which influences global temperatures, also weighed on the balance of 2023 and 2024. On the contrary, 2025 was characterized by the influence of La Niña, the phase that involves a rise of cold water in the Pacific and which tends to lower global temperatures in the northern hemisphere.
A blanket of harmful emissions
The inexorable increase in temperatures is the result of the equally rapid increase in carbon emissions that saturate the Earth’s atmosphere, and which in 2024 reached a new record, despite progress in decarbonization in energy production. According to a recently published World Meteorological Organization report, in 2024 CO2 concentrations in the atmosphere reached their highest level since measurements began 67 years ago.
A November of climatic extremes
In November 2025, global temperatures were 1.54°C higher than pre-industrial levels, making it the third warmest November on record, with exceptionally high temperatures in the Arctic Ocean and northern Canada. Sea ice in the Arctic is at its lowest level on record for this time of year.
But the records that perhaps most of all marked 2025 were those of extreme climate phenomena. The summer of 2025 was marked by heat waves in which the presence of climate change caused 16,500 additional deaths in Europe alone.
October 2025 brought Hurricane Melissa, the worst to ever hit Jamaica, leaving a trail of damage amounting to $8.8 billion. November was marked by a series of cyclones and catastrophic floods that affected millions of people and caused over 1,600 deaths in Sri Lanka, Indonesia, Thailand, Malaysia and Vietnam.
“We know that these extreme events increase in frequency and severity in a warmer world,” explains Samantha Burgess of the Copernicus Climate Change Service. “Storms get worse because the atmosphere holds more moisture.”
The question of +1.5 °C
In the Paris Agreement which turned 10 in 2025, world leaders committed to keeping the average global temperature well below +2°C and preferably within +1.5°C of the pre-industrial era by 2100, to avoid the most catastrophic effects of the climate crisis. Exceeding this threshold in a single year is a bad sign, but for science the limit must be interpreted on an average of 30 years. The hope of being able to bring global temperatures back below +1.5 °C after a few years of temporary exceeding is therefore still alive.
More worrying is the issue of exceeding climate tipping points, critical thresholds which, if exceeded, can cause significant and irreversible changes in the Earth system. According to a report published in October, before the start of COP30 climate work, one of these – the irreversible and widespread die-off of tropical coral reefs – has already been achieved.
