Cloud brightening, 'sun shields' to save Great Barrier Reef

SYDNEY • Australia announced plans yesterday to explore concepts such as firing salt into clouds and covering swathes of water with a thin layer of film in a bid to save the embattled Great Barrier Reef.

The Unesco World Heritage-listed reef, about the size of Japan or Italy, is reeling from two straight years of bleaching as sea temperatures rise because of climate change.

While the government has pledged to tackle climate change - the greatest threat to the world's largest living structure - there has also been a push to explore shorter-term measures to buy some time.

Canberra in January offered A$2 million (S$2 million) to attract innovative ideas to protect the site, which is also under pressure from farming run-off, development and the predatory crown-of-thorns starfish.

Six schemes selected out of a total of 69 submissions will be tested to see if they are feasible.

One selected concept is cloud brightening where salt crystals harvested from seawater are fired into clouds, making them more reflective and therefore deflecting solar rays back into space.

Australian Institute of Marine Science researcher David Mead said the proposal might seem wacky but it has real potential.

"The team has been looking at using a very fine nozzle to pump small droplets of salt water at the rate of several billion per second," he told national broadcaster ABC.

"The water vaporises and you're left with a salt particle which will float around, and if you can introduce those into the system you can increase the amount of sunlight reflected back."

Another idea was a biodegradable "sun shield", where an ultra-thin film containing light-reflecting particles covers some reef waters to protect corals from heat stress.

Other shortlisted projects include mass producing coral larvae with the aid of 3D-printed surfaces to support new growth, and large-scale harvesting and relocation of larvae.


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A version of this article appeared in the print edition of The Straits Times on July 21, 2018, with the headline Cloud brightening, 'sun shields' to save Great Barrier Reef. Subscribe