Scientists say 2025 ranked as the world’s third-hottest year ever recorded.

 

The Earth recorded its third-hottest year on record in 2025, continuing an unprecedented streak of extreme global heat, with scientists warning that no cooling relief is likely in 2026, according to US researchers and European climate monitors.

Data from the EU’s Copernicus Climate Change Service and California-based Berkeley Earth show that the past 11 years have been the warmest ever observed, with 2024 ranking first and 2023 second. For the first time, average global temperatures over the last three years exceeded 1.5°C above pre-industrial levels, Copernicus said in its annual report.

Berkeley Earth described the warming surge between 2023 and 2025 as “extreme,” suggesting the pace of global heating is accelerating. Scientists warn this trend threatens the goals of the 2015 Paris Agreement, which aims to keep long-term warming below 2°C and ideally at 1.5°C to avoid the most severe climate impacts.

UN Secretary-General Antonio Guterres has previously cautioned that breaching the 1.5°C threshold is now unavoidable, though swift cuts in greenhouse gas emissions could shorten the period of overshoot. Copernicus warned that the 1.5°C limit could be reached by the end of the decade—more than 10 years earlier than earlier projections.

In 2025, global temperatures averaged 1.47°C above pre-industrial levels, slightly cooler than 2023 but following the record 1.6°C set in 2024. About 770 million people experienced their hottest year on record, while no region recorded a cold-year average. Antarctica saw its warmest year ever, and the Arctic its second warmest.

Looking ahead, scientists caution that 2026 is unlikely to bring relief. Copernicus director Carlo Buontempo said rising temperatures make new records inevitable, especially if El Niño conditions develop. Berkeley Earth projects 2026 could become the fourth-warmest year since records began in 1850.

Meanwhile, efforts to curb greenhouse gas emissions—the main driver of climate change—are faltering in several developed countries. US emissions rose last year after two years of decline, while reductions slowed in parts of Europe. Researchers also noted that recent shipping fuel regulations reducing sulfur emissions may have unintentionally contributed to warming by limiting sunlight-reflecting aerosols.

Scientists stress that the overall trajectory is unmistakable: global temperatures are continuing to rise, and urgent action is needed to limit long-term damage.