Summer 2023 Breaks 2,000-Year Temperature Record, Alarming Study Finds

Summer 2023 has etched its scorching mark in history, establishing itself as the hottest season in the northern hemisphere in the past 2,000 years, according to a recent study published in the journal Nature. Comparing last year’s temperatures with historical climate data, researchers discovered that June, July, and August of 2023 were at least 0.5°C hotter than the most extreme past climates. This concerning trend was exacerbated by an El Nino weather pattern in the Pacific, which intensified the impact of human-caused global warming.

The study unveiled that summer temperatures over northern hemisphere land in 2023 soared 2.07°C higher than in the pre-industrial period (1850-1900), significantly surpassing the Paris Agreement’s target of limiting temperature increases to 1.5°C. This marked 2023 as the hottest year globally since records began in 1850, propelled by human-caused climate change, pushing northern summer highs beyond anything seen in two millennia.

Lead author of the study, Jan Esper, a professor of climatology at Germany’s Johannes Gutenberg University, emphasized the gravity of the situation, stating, “We shouldn’t be surprised. It’s the continuation of what we started by releasing greenhouse gases.”

Utilizing tree-ring data from various sites across the northern hemisphere, scientists estimated global temperatures between the first century AD and 1850, before the advent of modern observational instruments. The conservative estimate found that 2023 was at least 0.5°C hotter than the warmest northern hemisphere summer of that period in AD 246, and potentially 1.19°C warmer.

Co-author of the study, Max Torbenson, pointed out that 25 of the last 28 years exceeded the summer highs of AD 246, the hottest year before modern records began. By contrast, the coolest summer in that 2,000-year period was nearly four degrees cooler than the 2023 summer due to a major volcanic eruption. While volcanic activity could induce cooler conditions in the future, the study emphasizes that humanity’s release of greenhouse gases will persistently trap heat in the atmosphere.

Esper stressed the urgency of immediate action to curb emissions, stating, “The longer we wait, the more difficult and expensive it will be.”

In another study published recently, it was warned that higher temperatures and ageing populations would expose tens of millions of older people to dangerous heat extremes by 2050. Currently, 14 per cent of elderly people are exposed to days exceeding 37.5°C, a figure expected to rise to 23 per cent by mid-century, according to the study in Nature Communications.

Lead author of the latter study, Giacomo Falchetta, highlighted the disparities in preparedness and adaptive capacity across different regions. While Europe has systems to support people during heatwaves, Africa and Asia, with rapidly growing elderly populations, lack sufficient access to clean water and healthcare to cope with extreme heat.

“As climate change continues to be exacerbated by El Nino, temperature records are likely to be broken again in 2024,” warned Ulf Büntgen, a study co-author from the University of Cambridge. “2023 was an exceptionally hot year, and this trend will continue unless we dramatically reduce greenhouse gas emissions,” he added.

In recent weeks, exceptional heat waves have ravaged many Asian countries, with Myanmar experiencing its highest-ever April temperature of 48.2°C and parts of Delhi, India, recording temperatures as high as 50°C.

“When you look at the long sweep of history, you can see just how dramatic recent global warming is,” Büntgen concluded.