The UK’s longest-lasting snow patch, which has survived countless summers on a remote mountainside in the Cairngorms, has melted away for only the eighth time in 300 years as the Cop26 climate talks take place in Glasgow.Nicknamed “the Sphinx”, the hardy patch of snow is found on Braeriach, Scotland’s third-highest mountain at 1,296 metres (4,252ft), near Aviemore. It had shrunk to the size of an A4 piece of paper in recent weeks before finally disappearing in mild weather.Iain Cameron, an expert in snow cover who has been studying snow patches in Scotland for 25 years, said global heating was a significant factor. “How ironic and prescient it is that our longest-lasting patch of snow melted for the third time in five years, right on the eve of Cop26. Before 2000 it had melted only three times in the last 150 years.”According to records, the Sphinx previously melted fully in 1933, 1959, 1996, 2003, 2006, 2017 and 2018. Before 1933, it is thought to have last melted completely in the 1700s.Cameron, author of the book The Vanishing Ice, said warmer weather caused by the climate crisis “seemed to be the logical” explanation for the increased rate of melting. “What we are seeing from research are smaller and fewer patches of snow. Less snow is falling now in winter than in the 1980s and even the 1990s.”The Sphinx lies in Garbh Choire Mor, a hollow known as a corrie that was formed by ice or a glacier during the last ice age.A report commissioned by Cairngorms national park authority and published last year said declining snow cover had been observed on Cairngorm mountain since the winter of 1983-84. Researchers also noted a trend for increasingly warmer weather since the 1960s, and suggested that by the 2080s there would be some years with very little or no snow at all on Cairngorm.Before Scotland’s ski resorts were hit by coronavirus closures, they faced one of their most difficult seasons in 2019, with a lack of snow forcing many slopes to close.Lauren McCallum, of the international climate crisis campaign group Protect Our Winters, said the Cairngorms – and wider world – needed to be protected from further rises in temperature. She said: “We have to maintain a healthy temperature for our ecosystems and communities to survive.”