The content originally appeared on: CNN Brisbane, Australia (CNN)Australia's Great Barrier Reef is suffering its sixth mass bleaching due to heat stress caused by climate change, the reef's managers confirmed Friday. The update comes mid-way through a 10-day monitoring mission by UNESCO scientists as they consider whether to add one of the world's seven natural wonders to their 'in danger' list. The Great Barrier Reef Marine Park Authority (GBRMPA) and Australian Institute of Marine Science (AIMS) said Friday that aerial […]