The Great Barrier Reef is suffering a sixth mass-bleaching event. Here’s why scientists are concerned

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 surveys of around 750 reefs show widespread bleaching across the reef, with the most severe bleaching observed in northern and central areas. “More than half of the living coral cover that we can see from the air is severely bleached completely white and can have signs of fluorescence in the colors of pink, yellow and blue,” said AIMS coral biologist Neal Cantin. “The corals are producing these fluorescent pigments in an attempt to protect their tissue from heat and from the intense sun during these marine heatwaves.”He said countries and private businesses who invest in coal are costing the world its climate targets. And he said money spent on fossil fuels and subsidies was “a stupid investment leading to billions in stranded assets.””It’s time to end fossil fuel subsidies and stop the expansion of oil and gas exploration,” he said.Amanda McKenzie, CEO of the Climate Council, said the real issue the government should be addressing is climate change. “To give our reef a fighting chance, we must deal with the number one problem: climate change. No amount of funding will stop these bleaching events unless we drive down our emissions this decade,” she said in a statement.