Roman Warm Period
warm weather period, 250 BC to AD 400
The Roman Warm Period, or Roman Climatic Optimum, was a period of unusually-warm weather in Europe and the North Atlantic that ran from approximately 250 BC to AD 400. Theophrastus (371 – c. 287 BC) wrote that date trees could grow in Greece if they were planted but that they could not set fruit there. That is still the case today, which implies that South Aegean mean summer temperatures in the 4th and the 5th centuries BC were within a degree of modern ones. That and other literary fragments from the time confirm that the Greek climate was basically the same then as around 2000. Tree rings from the Italian Peninsula in the late 3rd century BC indicate a time of mild conditions there around the time of Hannibal's crossing of the Alps with imported elephants in 218 BC.
Dendrochronological evidence from wood found at the Parthenon shows variability of climate in the 5th century BC, which resembles the modern pattern of variation.
Cooling at the end of the period is noted in Southwest Florida, which may have been caused by a reduction in solar radiation reaching the Earth. That may have triggered a change in atmospheric circulation patterns.
The phrase "Roman Warm Period" first appears in a 1995 doctoral thesis. It was popularized by an article published in Nature in 1999.
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This entry incorporates text from “Roman Warm Period” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.