The Great Barrier Reef just saw its third mass coral bleaching event in five years as the impacts of climate change continue to destroy it. The importance of taking action on climate change and global heating cannot be understated if the reef is to be saved. However, scientists at Southern Cross University (SCU) have just conducted the worlds first ‘cloud brightening’ technique to protect corals in an attempt to give the reef more time for humans to take action on climate change.
The project aims to to shade and cool large areas of reef at risk of bleaching by spraying microscopic saltwater droplets into clouds to make them more reflective of sunlight. The trail that was recently conducted on a 20-by-20-kilometre area and aims to have a ten fold increase in the project area by 2022.
Project leader and SCU senior lecturer Dr Daniel Harrison said cloud brightening was one of the most innovative and promising potential methods that could protect very large areas of reef.
‘Cloud brightening could potentially protect the entire Great Barrier Reef from coral bleaching in a relatively cost-effective way, buying precious time for longer-term climate change mitigation to lower the stress on this irreplaceable ecosystem,’ Dr Harrison said.
‘Microscopic sea water droplets are sprayed into the air, evaporating 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.’
Every cloud droplet needs a nucleus to condense onto and Dr Harrison’s previous research identified that there might be a shortage of suitable nuclei during summertime conditions when coral bleaching occurs.
As part of the research for the first time they tested the atmospheric particle concentrations above the reef.
‘Nobody has previously measured atmospheric particle concentrations above the reef before and during bleaching conditions,’ he said.
‘We were amazed to see that the numbers of natural atmospheric nuclei were far lower than even I had suspected.’
The researchers are hoping that ‘In the future this technology might be able to be applied over the Great Barrier Reef to reduce the severity of coral bleaching during marine heat waves, cooling and shading the corals below.’
Action needed
Immediate action on climate change and a reduction in the emission of greenhouse gases, including CO2, is needed to save the reef says the Australian Marine Conservation Society (AMCS).
‘While investment into helping Reef ecosystems and communities is welcomed, what our Reef needs is the Morrison Government to deliver decisive action to reduce emissions,’ says Great Barrier Reef campaigner Shani Tager.
‘The solutions to climate change – our Reef’s biggest threat – are already available and ready to go. We just need politicians to invest in proven, existing technology like wind and solar, and implement Reef safe climate policies that will ensure a bright future for our Reef, the wildlife and Queenslanders it supports.’
He pints out that without action on climate change and serious cuts to emissions then it ‘will be like pushing water uphill with a rake’.
‘If Australian science can lead the way in adaptive solutions then why can’t the Australian government lead the way in emission reductions, setting an international example as custodians of our Reef?’ said Mr Tager.
