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Can artificial clouds save the Great Barrier Reef?

In 2018, a study reported that half of the world’s largest coral reef system had died. Research teams in Australia are testing ways to alter clouds in hopes to salvage what remains.

Australia’s $300 million Reef Restoration and Adaptation Program is investigating and developing new technologies that will prolong the life of the Great Barrier Reef. One of its newer methods involves a repurposed ferry, a gigantic mist machine, and seawater.

In its most recent experiment, nanodroplets of seawater were blown out of 320 jets from the backend of a ferry as it floated 100km offshore. Sensors and drones tracked these droplets as they successfully drifted up into the atmosphere.

The idea is that these droplets would absorb into the clouds – brightening them, blocking sunlight, and providing cooling shade for the reefs below. It was the first trial in the world of this kind, and though the first attempt didn’t significantly alter the clouds, it did prove that it is possible.

You’re probably thinking: are humans really going around spraying seawater into the atmosphere, attempting to improve cloud cover to better protect reef colonies from the sun?

I’m here to let you know, yes. Yes, we absolutely are.

Posing a serious threat to the 2,300km coastal reef are environmentally damaging processes we’ve become familiar with here at Thred – climate change, ocean acidification, and warming seas.

And although coral reef restoration projects are taking place around the world, these efforts will be unsuccessful if the surrounding waters don’t provide a stable enough environment, such as the correct pH levels and temperature – both of which are affected by global warming.

The ‘cloud-brightening’ project, run by oceanographers and engineers at Southern Cross University, is motivated by the future possibility that humans will be forced to interfere with Earth’s weather systems to manage these drastic effects of climate change.

As news broke about the trial, scientists around the world became sceptical, as they usually are when altering natural elements within the Earth’s ecosystem is proposed.

In response, David Harrison, the leader of the project, underlined that (if successful on a large scale) cloud brightening should not be viewed as a technological substitute for ongoing efforts to halt climate change.

Instead, Harrison said, it should be used to help sustain reefs while CO2 emissions drop off. Still in its testing stages, cloud brightening could offer some protection for these corals as we transition to cleaner, greener energy. A temporary band aid during the healing process if you will.

But even as Australian oceanographers become confident that boosting up cloud cover could work, by incorporating higher pressure during the misting, and new instruments for measuring how nanodroplet particles interact with clouds, they remain cautiously optimistic about the project.

‘There are only so many clouds available, and there is only so much you can brighten them,’ said Harrison. ‘Eventually, climate change just overwhelms things.’

So, even if this reef-protecting project becomes a worldwide practice, governments still need to get their heads out of the clouds and start creating stronger policies to reduce greenhouse gas emissions. See what I did there?


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