Ski resorts across Europe have been left snowless this winter as temperatures spike. Those at lower altitudes have been particularly hard hit, with almost a third of European resorts – from Austria’s Tyrol mountains to France’s Auvergne-Rhône-Alpes – currently forced to close. As the climate heats up, the problem is getting worse. Since the 1960s, there have been five fewer snow days every decade in the French Alps, according to weather service Météo France. Research published last year in the journal Nature showed that if global warming reaches 2°C above pre-industrial levels, more than half …