August 2023 tied the record for the hottest month ever recorded globally, according to the European climate agency Copernicus Climate Change Service. The milestone was driven by a combination of long-term climate change and the strengthening influence of the El Niño weather phenomenon, which typically raises ocean and air temperatures across large parts of the world.
The finding adds to a string of alarming climate benchmarks in 2023. Scientists and meteorologists had already flagged earlier in the summer that July 2023 was the hottest month on record at the time, making the back-to-back records in consecutive months a particularly stark illustration of accelerating global warming. El Niño, a natural but cyclical warming of surface waters in the central and eastern Pacific Ocean, has compounded the underlying warming trend caused by greenhouse gas emissions, pushing temperatures to new extremes.
Copernicus, which is funded by the European Union and operates one of the world’s most closely watched global temperature monitoring systems, tracks surface air temperatures using satellite data and ground-based observations. Its monthly bulletins are widely cited by climate scientists and policymakers as a key indicator of how rapidly the planet is warming relative to pre-industrial baselines.
The record August temperatures have broad implications beyond the data itself. Extreme heat is linked to a range of secondary effects including drought, wildfires, stress on food and water supplies, and increased mortality, particularly among elderly and vulnerable populations. The compounding of a natural El Niño cycle on top of human-caused climate change raises concerns among scientists about what future summers could look like as baseline temperatures continue to rise.
Climate scientists have warned that records of this nature are no longer isolated anomalies but are becoming an expected feature of a warming world, and that without significant reductions in carbon emissions, such extremes will grow more frequent and more severe.