For decades, tucked away inside English churches, a surprising source of climate data has remained largely unnoticed: organ-tuning books. Researchers at Nottingham Trent University have uncovered these historical records, revealing a measurable rise in temperatures within church buildings over the past half-century. This discovery highlights how even seemingly unrelated archives can provide valuable insights into long-term environmental changes.
The Unexpected Data Source
Organ tuners, responsible for maintaining the complex mechanics of pipe organs, traditionally keep detailed logs of their work. These books often include notes on environmental conditions, like temperature and humidity, because even slight fluctuations can dramatically affect an instrument’s tuning. As researcher Andrew Knight explains, these notebooks are “goldmines” of historical climate data – spanning decades in some cases.
The Findings: A Gradual Warming
A recent study published in Buildings & Cities analyzed records from 18 organ-tuning books in London, Nottinghamshire, and Derbyshire, dating back to 1966. The data shows a clear trend: average temperatures inside churches have risen during both winter and summer months. This suggests that buildings are being heated more consistently today than in the past, but also that they are warming even when heating systems are off.
Specifically, the average summer temperature in urban churches climbed from 17.2°C in the late 1960s to 19.8°C in the 2020s. This change is not merely anecdotal; it’s a quantifiable shift in ambient temperature.
Why Organs Matter to Climate Studies
The sensitivity of organs to temperature and humidity makes them a unique indicator of climate change. Even a one-degree Celsius shift can alter an organ’s pitch by 0.8 hertz. This means that an instrument tuned at 16°C will sound noticeably different when temperatures rise to 20°C. The effect is significant enough that organ builders and tuners are acutely aware of it.
Neil Macdonald, a professor of geography at the University of Liverpool, notes that this is an entirely new source of climate data. While factors like ventilation may also influence internal temperatures, the consistent warming trend documented in the tuning books strongly suggests broader environmental shifts.
The Global Impact
The challenge of keeping organs in tune is already acute in hot climates like Nigeria, Malaysia, and India. Rising global temperatures threaten to exacerbate this issue, making maintenance even more difficult. Meanwhile, powerful heating systems in colder regions can also throw instruments out of tune, compounding the problem.
Researchers hope to expand their analysis by collecting more organ-tuning books, particularly older records. As Yangang Xing emphasizes, these seemingly obscure archives hold significant value for understanding long-term climate trends. The value of these tuning books is now clear: they are a unique and valuable historical record of climate change.
