The past 11 years (to 2025) are the warmest since records began, with the past three at the top of the leader-board. The hottest year on record was 2024, which coincided with a strong El Niño and a peak of the 11-year solar cycle. The year 2025 was the third hottest despite a La Niña pattern (which tends to cool temperatures) and a dimming solar cycle—making it the hottest La Niña year ever recorded.
The most recent previous La Niña year, 2022, was 1.15°C warmer than the world's preindustrial average temperature, according to the World Meteorological Organisation. The year 2025 was 1.44°C warmer. The average warming over preindustrial levels across 2023–25 has been between 1.48°C and 1.50°C, depending on the dataset.
Several lines of evidence suggest a sustained acceleration. Manmade greenhouse-gas emissions, especially of carbon dioxide, continue to increase. Paradoxically, a reduction in sulphate-particle pollution—driven by stricter regulation of cargo ships and Chinese coal-fired power plants—has also contributed to faster warming. Sulphates reflect solar radiation back into space; stripping them from the atmosphere is a hygienic boon but removes a cooling effect.
A joint study published in January 2026 by climate researchers at the University of Exeter and members of Britain's Institute and Faculty of Actuaries suggested that climate sensitivity—the degree to which the climate responds to greenhouse gases—may be at the upper end of mainstream estimates. If so, the global temperature rise could pass 2°C by mid-century. Climate models show that the effects of global warming, including the risk of irreversible tipping points, are much greater beyond 2°C than the 1.5°C enshrined in the UN Paris agreement, signed in 2015.
In the early 2000s a so-called "climate hiatus" saw temperatures persistently lower than models predicted, as several natural climate cycles temporarily conspired to cool things. Many climate scientists are therefore cautious about drawing grand conclusions from the exceptional post-2023 warmth.
February 2025 saw the lowest ice cover across both poles since satellite observations began in the late 1970s. Antarctica experienced its hottest year on record in 2025.
American scientists have historically been leaders in climate-data collection. The Mauna Loa observatory in Hawaii holds the longest-running observations of atmospheric carbon-dioxide concentrations. The National Snow and Ice Data Centre at the University of Colorado, Boulder, holds unique databases on the annual ebb and flow of sea ice at both poles. America owns 58% of the roughly 4,000 Argo floats which drift at depth across the world's oceans, gauging their health before popping up to the surface every ten days or so to broadcast their data home. The Argo floats have built the best evidence there is of how the oceans' heat content is increasing—an important trend because the oceans have absorbed more than 90% of the extra heat trapped in Earth's system by greenhouse gases.
The Trump administration has decommissioned long-standing databases, deleted key reports and analyses, and fired or reassigned the staff with unique expertise. The Billion-Dollar Weather and Climate Disasters database, maintained by NOAA since 1980 and recording natural disasters causing at least $1bn in damages, was retired in 2025. The EPA proposed eliminating or suspending all industry greenhouse-gas reporting requirements—until 2034 for some industries, permanently for others. The National Climate Assessments, legally mandated every four years, were removed from government servers and the contract with the group that produces them was terminated; the next assessment was due in 2027.
Adam Smith, the researcher who previously ran the Billion-Dollar Weather and Climate Disasters project for NOAA, was hired by Climate Central, a climate non-profit, to continue the dataset from there.
Europe's Copernicus Climate Change Service is a key monitoring body. Its director, Carlo Buontempo, has said the question is no longer whether the 1.5°C threshold will be overshot but how to manage the overshoot. The centre has calculated that the loss of American data would have only a small impact on its forecasts. "We are resilient," says Buontempo.
If you're careful enough, nothing bad or good will ever happen to you.