Originally, Childe believed that the settlement dated from around 500 BC. This interpretation was coming under increasing challenge by the time new excavations in 1972–73 settled the question. Radiocarbon results obtained from samples collected during these excavations indicate that occupation of Skara Brae began about 3180 BC with occupation continuing for about six hundred years. Around 2500 BC, after the climate changed, becoming much colder and wetter, the settlement may have been abandoned by its inhabitants. There are many theories as to why the people of Skara Brae left; particularly popular interpretations involve a major storm. Evan Hadingham combined evidence from found objects with the storm scenario to imagine a dramatic end to the settlement: