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19.06.2021 9:21:17
“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,” he warned. [SCU]
See full version: Cloud Brightening Is Being Tested Over The Great Barrier Reef
“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,” he warned. [SCU]
He also said the effectiveness of the cloud-brightening technique would drop significantly as the ocean warms further. That means the process would be similar to putting the reef on life-support while the underlying challenge of climate change was addressed.
The experiment was carried out by the university and the Sydney Institute of Marine Science late last month, just before a comprehensive scientific survey found that the reef had suffered its most widespread coral bleaching on record.
To have a significant impact on the reef, a full-scale experiment would need to be 10 times larger, involving the use of several big barge-mounted turbines, Harrison said. But, he added, “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.”
Now, an ambitious “cloud brightening” experiment has been carried out over Australia’s Great Barrier Reef. Scientists hope this could become a futuristic way to protect coral reefs.
Earlier this month we wrote about a recent bleaching event in Australia. This is the third widespread bleaching event in five years, and firsthand account from Ultra Coral Australia, describes this year’s event as the most severe deepwater bleaching they have ever seen.
“We tested the hypothesis at one-tenth of the scale we’re aiming for. and showed how we can successfully create hundreds of trillion of these sea salt crystals per second, which float up into the atmosphere to bolster the reflectivity of the existing clouds,” Harrison said. [links]
A research team now says they’ve successfully tested a new technique called “cloud brightening” that could buy humanity some time in the race to slow climate change and save threatened corals. more
“Cloud brightening could potentially protect the entire Great Barrier Reef from coral bleaching in a relatively cost-effective way,” said project leader Dr. Daniel Harrison from Southern Cross University . “Microscopic sea water droplets are sprayed into the air, evaporating (and) leaving just nano-sized sea salt crystals, which act as seeds for cloud droplets, brightening existing cloud and deflecting solar energy away from the reef waters when heat stress is at its maximum.” more
GREAT BARRIER REEF, AUSTRALIA - NOVEMBER 20: Aerial view of coral banks, reef systems and the . [+] pacific ocean on November 20, 2015 in Great Barrier Reef, Australia. (Photo by EyesWideOpen/Getty Images)
“We welcome scientific research where indigenous people and the rest of Australia work together to maintain the reef ecosystem for future generations,” said Usop Drahm, a traditional owner from Manduburra who joined the experiment. “This technology might help prevent bleaching and we like that it uses no chemicals and relies on natural processes.”
The process may look familiar to skiers. It’s similar to snow-making, in which water treated with harmless chemicals is sprayed into freezing air where it freezes into crystals we recognize as snowflakes. The difference, as Harrison explains, is that water sprayed over the ocean is in the form of finer droplets that evaporate rather than freeze so that the remaining crystals stay in the air and encourage more robust cloud formation instead. more
But it could be a while before we find out if swarming robots is an answer for saving reefs. The researchers hoped to raise about $100,000 on Kickstarter, but weren’t able to reach their goal. [links]
It’s reached the point where some scientists think they can no longer rely on natural forces to keep reefs alive; instead they’re developing ways to use technology to save them. A team of British researchers, for instance, believes geoengineering is called for. Their idea is to turn clouds into umbrellas that would protect reefs by bouncing more sunlight back into space. more
Clouds as umbrellas more
Now, as we slide into the last weeks of summer, is Bradbury seeming more prescient? Is it clearer that we’re a year closer to the demise of one of more diverse and vibrant ecosystems the Earth has seen? Most experts would tell you no, that they’re not ready to concede coral reefs are going the way of dinosaurs. But they haven’t had much reason to be more hopeful, either.
Video bonus: Take a breather and see what’s going on at the bottom of the sea. Check out NOAA’s live-streaming video camera.
They would do this by spraying tiny droplets of seawater up into the clouds above the reefs, which would have the effect of making the clouds last longer and cause their tops to brighten and reflect more sunlight. That should lower the water temperature and slow any bleaching of the coral down below. more
Critics also worry that Australia is setting the wrong kind of precedent by rebranding a solar-geoengineering experiment that could have regional impacts as a local adaptation project. “One could say that there should have been some level of consultation with the outside world,” says Janos Pasztor, who heads the Carnegie Climate Governance Initiative, an advocacy group in New York City that has been pushing for a global debate over geoengineering governance in the United Nations. more
“It sort of speeds up the whole path from research to implementation in the field,” says van Oppen. [links]
In 2018, the Australian government allocated Aus$6 million to a consortium of universities and government research institutes for a feasibility study focused on potentially radical strategies that could be applied across the reef. Researchers reviewed some 160 ideas, including putting live corals on ice for long-term preservation and synthetically engineeering new varieties that can tolerate the warmer waters. Many approaches proved too costly and energy intensive, but 43 interventions were singled out for further study. Marine cloud brightening drew support in part because it theoretically provides direct relief precisely when and where corals need it most. [links]
That’s enough to keep Harrison going, and his team is already preparing for a trip into the field in 2022. The scientists plan to run the mist machine at higher pressure, which should produce a sixfold increase in the number of particles, and they will use new instrumentation to determine how particles alter clouds. They are also investigating an entirely different nozzle technology that could reduce the number of nozzles needed by a factor of 1,000.