There's hope for the Great Barrier Reef yet: New 'cloud brightening' project aims to save vulnerable coral

This early-stage experiment looks to protect coral from global warming and mass bleaching in a futuristic new way

Australia's Great Barrier Reef suffered its most widespread coral bleaching on record, scientists said on April 7, 2020 in a dire warning about the threat posed by climate change to the world's largest living organism. AFPShow less

One silver lining we've seen come from social distancing measures taken during the outbreak of Covid-19 has been the positive impact on the environment. A decrease in pollution levels and thriving wildlife are just two examples that have been noted here in the UAE.

But the damage already done to this planet is widespread. The devastating impacts of global warming are particularly clear in Australia, where the Great Barrier Reef, the Earth's largest coral reef system and one of the seven natural wonders of the world, is highly vulnerable.

In the past few decades, the reef has lost more than half of its coral cover, pollution has caused deadly starfish outbreaks and it's endured mass coral bleaching, according to the World Wildlife Fund.

An example of coral bleaching at the Great Barrier Reef. AFP

Now, a small group of scientists hope to save it from the brink of extinction, with an ambitious new "cloud brightening" project they hope could become a futuristic way of protecting coral from the effects of global warming.

What is 'cloud brightening'?

The idea is to cool the waters around the reef by making clouds reflect more sunlight. Researchers used a fan, which was mounted on a boat, to shoot salt crystals into the air.

The project's lead scientist, Daniel Harrison, from Southern Cross University in Lismore, Australia, told AFP the results from the initial early-stage trial were "really, really encouraging".

If we keep going on business-as-usual-type emission scenarios, then at most this technology can just buy a couple of extra decades

"All the research is theoretical ... so this an absolute world first to go out and actually try and take seawater and turn it into these cloud condensation nuclei."

While the experiment was a success, Harrison also emphasised that at least four more years of research would be needed in order to prove the theory. Then, to have a significant impact, an experiment that is 10 times larger would need to be undertaken.

"If it works as well as we hope then maybe we could reduce the bleaching stress by about 70 per cent ... potentially nearly all of the mortality," Harrison added.

Yet, as oceans warm further, Harrison also said the cloud-brightening technique could become less effective.

"If we keep going on business-as-usual-type emission scenarios, then at most this technology can just buy a couple of extra decades before we see the complete loss of the reef."

The experiment was a collaboration between the university and the Sydney Institute of Marine Science. It took place in late March, just as a survey found the reef had suffered its most widespread coral bleaching on record.

It was the third mass bleaching event in the past five years and raised fears that much of the coral could be permanently damaged.

Is cloud brightening similar to cloud seeding?

Here in the UAE, we use a method called cloud seeding, which artificially encourages a cloud to produce rain.

Is it similar to cloud brightening? Yes and no.

Cloud seeding planes are fitted with special flares that are loaded with salt crystals and fired into convective, or warm, clouds that have an updraft – or rising current of air.

The updraft then sucks up the salt crystals into the cloud, and they attract tiny particles of water that collide, becoming heavier and then falling as rain.

Last year, the UAE conducted 242 missions, which was up from 177 in 2016.

So the method is similar, but the outcome and aims are completely different.