The world felt the heat in a surprising way this September, breaking temperature records and leaving the scientific community in awe. Following record-breaking temperatures in July and August – the latter recognized as the hottest month ever – September continued the alarming trend. Such escalating temperatures have been the culprits behind the surge in heatwaves and devastating wildfires across the globe.
September 2023 surpassed the previous heat record for the month by a staggering 0.5°C, representing the most significant temperature spike ever recorded for the month. Overall, September was approximately 1.8°C warmer than pre-industrial levels. This astonishing data, mirroring a concerning trajectory, was corroborated by both European and Japanese climate researchers.
Two main drivers are behind this heating phenomenon: the unabated release of carbon dioxide emissions and the swift emergence of an El Niño event. The preceding three years were dominated by La Niña conditions in the Pacific Ocean, a phenomenon that slightly reduces global temperatures by storing more heat in ocean waters. However, a shift to El Niño has seen the release of this stored oceanic heat, contributing to rising global temperatures. Given this pattern, 2023 is poised to be the hottest year on record, with 2024 potentially eclipsing even that.
Zeke Hausfather of the Berkeley Earth climate data project expressed his shock, stating that the September climate data was “absolutely gobsmackingly bananas.” Mika Rantanen, from the Finnish Meteorological Institute, shared the disbelief, finding it hard to fathom the enormous jump within a single year. The University of Reading’s Prof Ed Hawkins labeled the summer’s heat as “extraordinary.”
Samantha Burgess, from the EU’s Copernicus Climate Change Service, voiced deep concern. She highlighted the staggering difference in September’s temperatures and emphasized that 2023 is set to be the warmest year ever, being about 1.4°C above the pre-industrial average. As the UN climate conference, Cop28, looms large, Burgess insists that the need for decisive climate action has reached a critical juncture.
Countries across Europe, including France, Germany, and Poland, reported record-breaking temperatures. Similarly, the UK experienced one of its hottest Septembers, with data tracing back to 1884. Down under, Australia’s climate scenario is also grim. Joelle Gergis, a climate scientist, warned of shocking observations, noting that numerous regions saw temperatures 3°C to 5°C above the usual, with looming threats of droughts and a potentially harsh summer ahead.
While the dominant factors causing these soaring temperatures are human-induced global heating combined with El Niño, Zeke Hausfather points out other minor contributors. These encompass an increase in the 11-year solar cycle, reductions in sun-blocking sulphur emissions, and the aftereffects of a volcanic eruption in Tonga which released vast amounts of heat-trapping water vapor.