Last year’s northern hemisphere summer, noted for its intense heat waves that triggered wildfires across the Mediterranean, road damage in Texas, and overstrained power grids in China, is now confirmed to be the warmest in approximately 2,000 years, according to new research findings. This alarming milestone was highlighted in one of two studies published on Tuesday, revealing a continuous rise in both global temperatures and climate-warming emissions.
“Looking at the long sweep of history, you can see just how dramatic recent global warming is,” said Jan Esper, a climate scientist at Johannes Gutenberg University in Germany and co-author of the study published in the journal Nature. Researchers utilized meteorological records dating back to the mid-1800s and analyzed tree ring data from nine northern sites to compare temperatures, establishing last year’s summer as unprecedented over a lengthy historical period.
The studies indicate that the 2023 summer temperatures on lands between 30 and 90 degrees north latitude were 2.07 degrees Celsius (3.73 degrees Fahrenheit) higher than pre-industrial averages. Additionally, tree ring data revealed that the summer months in 2023 averaged 2.2 degrees Celsius (4 degrees Fahrenheit) warmer than the estimated average temperature from years 1 to 1890.
The significant findings coincide with data from the European Union’s Copernicus Climate Change Service earlier this year, which hinted that 2023 was “very likely” the warmest year in about 100,000 years. However, Esper cautioned that establishing such long-term records with current scientific methods remains challenging.
The study further underscores the impact of the El Nino climate pattern, which exacerbated last year’s heat conditions, leading to “longer and more severe heatwaves, and extended periods of drought,” according to Esper.
In related findings, a study published in PLOS Medicine detailed the human toll of heatwaves, linking them to over 150,000 deaths annually in 43 countries between 1990 and 2019. This accounts for about 1% of global deaths annually, mirroring the death toll of the global COVID-19 pandemic. The research indicated that more than half of these deaths occurred in Asia, while Europe faced the highest per capita toll, particularly in Greece, Malta, and Italy.