近年全球珊瑚白化问题空前严重

Unprecedented¹ coral bleaching² in consecutive³ years has damaged two-thirds of Australia's Great Barrier Reef, aerial surveys have shown. , ,航空勘测发现 ，近年连续发生的珊瑚白化问题空前严重，澳大利亚三分之二的大堡礁已遭到重创。, ,The bleaching - or loss of algae ⁴ - affects a 1,500km (932 miles) area of the reef, according to scientists. , ,The latest damage is concentrated in the middle section, whereas last year's bleaching hit mainly the north. , ,Experts fear the proximity ⁵ of the two events will give damaged coral little chance to recover. , ,Prof Terry Hughes, from James Cook University, said governments must urgently address climate change. , ,"Since 1998, we have seen four of these events and the gap between them has varied ⁶ 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 ⁷ and transition away from fossil fuels to renewables, the better."