As heat waves continue to scorch regions across the globe, scientists are reporting that this summer has been the hottest on record – and by a significant margin. According to data from the European Union's Copernicus Climate Change Service, the period from June to August has been the warmest such period since records began in 1940. The global average temperature this summer was 16.77 degrees Celsius (62.19 Fahrenheit), surpassing the previous record set in August 2019 by nearly 0.3 degrees Celsius.
What's remarkable about this record is that it was broken by a significant difference, unlike previous records that were only broken by hundredths of a degree. This confirms what many had already suspected – this summer has been scorching hot for large parts of the Northern Hemisphere, including the United States, Europe, and Japan, with unprecedented heat waves and soaring ocean temperatures.
The hottest June on record was followed by the hottest July, breaking previous records by large margins. And now, August has also set a record as the warmest such month on record, except for July. The global average temperature in August was 16.82 degrees Celsius, surpassing the previous record set in 2016 by 0.31 degrees Celsius.
António Guterres, the secretary-general of the United Nations, described this summer as the "dog days" that are not just barking but biting. He emphasized that scientists have long warned about the consequences of our fossil fuel addiction, and it is clear that our climate is deteriorating faster than our ability to cope with extreme weather events that are affecting every corner of the planet.
Both July and August have exceeded the estimated 1.5 degrees Celsius threshold, compared to pre-industrial levels, which scientists have long warned is crucial to prevent the most catastrophic impacts of climate change. Although scientists focus more on long-term global temperature rises, these temporary breaches provide a glimpse into what summers will be like at 1.5 degrees of warming.
The extreme heat of this summer has been accompanied by devastating wildfires, health problems, disruptions in daily life, and lasting environmental damage. The Northern Hemisphere has experienced a summer of extremes with repeated heatwaves. Meanwhile, countries in the Southern Hemisphere have also witnessed unusually warm winters, with well-above average temperatures recorded in Australia, several South American countries, and even Antarctica.
Remarkably, global average ocean temperatures have also soared, contributing to the strengthening of major hurricanes in the Atlantic and typhoons in the Pacific. In July, a sudden marine heatwave off the coast of Florida led to ocean temperatures reaching "hot tub" levels. Furthermore, in June, parts of the North Atlantic experienced a "totally unprecedented" marine heatwave with temperatures up to 9 degrees Fahrenheit higher than usual.
The Copernicus data shows that every day from the end of July to the end of August saw ocean temperatures surpass the previous record set in 2016. Whether this year will end up being the warmest on record is not yet certain, but it is highly likely. With four months remaining in the year, 2023 currently ranks as the second warmest on record, just 0.01 degrees Celsius below 2016, which is currently the warmest year on record.
Scientists predict that next year could be even hotter due to the arrival of El Niño, a natural climate fluctuation that brings warmer-than-average sea surface temperatures and influences weather patterns. Samantha Burgess, deputy director of Copernicus, warned that this summer has seen numerous record-breaking events and emphasized that it will only get worse if we continue burning fossil fuels, which contribute to global warming.
The release of the Copernicus data coincided with the US National Oceanic and Atmospheric Administration's State of the Climate report for 2022 – an annual assessment of the planet's health. The report revealed record ocean heat and global sea levels last year, along with unprecedented levels of greenhouse gas emissions in the atmosphere, reaching the highest levels in at least 800,000 years.