collaboration. The series of severe droughts and heat waves in Europe since 2014 is the most extreme for more than 2,000 years, research suggests. Get top stories in your inbox. Our award-winning journalists bring you the news that impacts you, Canada, and the world. Don't miss out. Email * The study analyzed tree rings dating as far back as the Roman empire to create the longest such record to date. The scientists said global heating was the most probable cause of the recent rise in extreme heat. The heat waves have had devastating consequences, the researchers said, causing thousands ofear...