Coral reefs around the world look increasingly threatened, with news this week from Australia that perhaps 35 per cent of the northern and central Great Barrier Reef has been destroyed because of coral bleaching.
Terry Hughes, the lead scientist studying the reefs off Australia's east coast, tweeted that the results are "the saddest, most confronting" of his career.
Between 1950 and 2008, the world lost about 20 per cent of its coral reefs. This year, the immediate challenge has been the warm ocean temperatures produced by the 2015-16 El Nino, which is now dissipating.
But global warming provides the long-term challenge for coral reefs' survival.
Coral reefs may only cover 0.015 per cent of the planet's ocean area, but they account for more than one quarter of the oceans' biodiversity.