Two years in a row has produced unprecedented bleaching of the coral on the Great Barrier Reef, about 900 miles or 1,500 km has been affected, nearly two thirds.Last year it was mainly in the north but this year the center has been affected.
“Since 1998, we have seen four of these events and the gap between them has varied substantially, but this is the shortest gap we have seen,” Prof Hughes told the BBC.
“The sooner we take action on global greenhouse gas emissions and transition away from fossil fuels to renewables, the better.”
“The central third this year, I would say, was as severe in terms of bleaching as what we saw as the northern third last year,” he told the BBC.
“For those reefs that were hit two years in a row, it is effectively a double whammy. They have had no chance to recover from last year’s events.”
“Coral bleaching is caused by rising water temperatures. Exacerbated by man-made climate change, as the oceans are absorbing about 93% of the increase in the Earth’s heat.
Bleaching happens when corals under stress drive out the algae known as zooxanthellae that give them colour. If normal conditions return, the corals can recover, but it can take decades, and if the stress continues the corals can die.”-bbc