When it comes to producing definitive proof of climate change, one limitation is the lack of data about past weather conditions. In a newly published study in the journal Weather, Spanish scientists turned to an unexpected source for help- manuscripts from Arabic scholars, written in the 9th and 10th centuries.
The study, "How useful could Arabic documentary sources be for reconstructing past climate?", examines documentary texts by contemporary historians and political commentators. They do not explicitly record weather and climate conditions, but their references to events such as floods, droughts and snowfall provide valuable information- especially since their authors worked in Baghdad.According to the study's lead author, Dr Fernando Domínguez-Castro, the sources together evidence a temperature drop in Iraq in the 10th century and a higher number of extreme weather events and severe cold weather than today. The authors do not directly apply those findings to today's climate situations, but see their work as a small piece in a very large picture. "The ability to reconstruct past climates provides us with useful historical context for understanding our own climate," said Domínguez-Castro, reported Science Daily.
Of course, such human sources are only available in rare situations, and not at all for the era before the advent of the written word (unless we find particularly helpful cave paintings). But given the gravity of the threat of climate change and the remarkable stubbornness of those who deny it, every effort to complete the picture is valuable.