Tourism authorities around the world have expressed concern at a warning from scientists that the world’s third mass coral bleaching event will begin early next year and may damage about 38% of the planet’s coral reefs.
The coming event is predicted to be the worst on record. Reefs around the world, including in Australia, Hawaii and the Caribbean, could be affected. The world’s largest coral reef, the Great Barrier Reef, about the size of Japan, is a mainstay of tourism for Queensland and a priceless natural asset for all humanity.
Bleaching, caused by consistently warmer than average ocean temperatures, turns corals white or fades their colours. It doesn’t necessarily kill coral; that depends on other factors, including how long the event lasts.
The first mass coral bleaching, in 1998, affected about 16% of the world’s reefs and killed up to 10% of Great Barrier Reef corals.
A before and after image of coral bleaching in American Samoa. The first image was taken in December 2014. The second image was taken in February 2015 when the XL Catlin Seaview Survey responded to a coral bleaching alert.
The second event was in 2010, but the cooling effect of several storms saved the Great Barrier Reef from the worst effects.
A new study by the US National Ocean Atmospheric Administration (NOAA) and the University of Queensland (UQ) has forecast that the looming warming event could be the worst on record, as ocean temperatures climb increasingly high.
The UQ’s Global Change Institute director Professor Ove Hoegh-Guldberg predicts the impact on the Great Barrier Reef will be significant. See accompanying article by Professor Hoegh-Guldberg: The oceans are becoming too hot for coral, sooner than we expected
“If conditions continue to worsen, the Great Barrier Reef is set to suffer from widespread coral bleaching and subsequent mortality, the most common effect of rising sea temperatures,” Hoegh-Guldberg said.
Tourism authorities stress that the Great Barrier Reef is enormous and effects are likely to be localised.
Caribbean waters are warming already, threatening coral in Puerto Rico and the US Virgin Islands, NOAA scientists say. Coral bleaching began in the Florida Keys in August, but now scientists expect bleaching conditions there to diminish.
In Hawaii, the current high ocean temperatures follow bleaching in the main Hawaiian Islands in 2014 – only the second bleaching occurrence in the region’s history.
The problem, caused by climate change, is bigger than Australia or any other single country. It is believed to be linked to carbon emissions, which are in turn linked to increased industrialisation and a human population explosion from 2.5 million people in 1950 to 7.3 billion now.
Population is expected to reach 9.7 billion by 2050. According to the United Nations, nine countries will account for half the world’s population growth between now and 2050: India, Nigeria, Pakistan, the Democratic Republic of Congo, Ethiopia, Tanzania, the US, Indonesia and Uganda. Only one of those however, is highly industrialised. Others are striving for the same goal, which brings consequences.
Written by Peter Needham