Marine Cloud Brightening

ASSOCIATE PROFESSOR DANIEL HARRISON: Coral reefs are just an incredible ecosystem. They cover less than 1% of the surface of the earth, but 25% of all marine life rely on them. 

DR SOPHIA ELLIS: Such a beautiful landscape that lives in such harsh environments. 

ASSOCIATE PROFESSOR DANIEL HARRISON: Over the last 10 years, we've had six mass bleaching events. And in some of those episodes, we've lost up to half the coral. 

MAX TAVERNER: There's a whole ecosystem there. And if you start removing certain parts of that, the whole system collapses in on itself. 

ASSOCIATE PROFESSOR DANIEL HARRISON: We wondered whether there was something we could do to cool the water back down and stop the corals bleaching. Few years ago, we did some modelling with the CSIRO and they were looking at all of the different interventions that you might be able to apply to help protect the Great Barrier Reef. And Marine Cloud Brightening was the clear standout in its ability to actually help to preserve the Great Barrier Reef for future generations. 

DR REZA SEDIGHI: Marine Cloud Brightening actually works by atomizing seawater into tiny droplets towards marine clouds. These particles help clouds to become brighter. 

MAX TAVERNER: We reflect more light back out into space and we keep the water around those sensitive coral reef cooler. This is all about enhancing existing cloud coverage over the Great Barrier Reef. 

DR SOPHIA ELLIS: This intervention could be a really good solution for protecting reefs locally while we come up with more interventions and more solutions for the Great Barrier Reef. 

ASSOCIATE PROFESSOR DANIEL HARRISON: So we just bring in our own. The nozzles are really one of the key underpinning technologies of the entire concept because we use those to take the seawater and blast it apart into thousands of trillions of nanosized droplets per second which are then able to seed individual cloud droplets and brighten the clouds. 

MAX TAVERNER: About a thousand trillion droplets for every nozzle and we've got 640 nozzles on our current system. Stacks up pretty quickly. 

ASSOCIATE PROFESSOR DANIEL HARRISON: We have a ship out at sea creating the sea salt that brightens the clouds. We have other ships measuring what's going on. We use drone and aircraft to fly and map where those extra sea salt crystals are going and then to fly through the clouds and look at how the brightness and the and the properties of the clouds are changing in response. 

MAX TAVERNER: These are all like a swash plate. 

ASSOCIATE PROFESSOR DANIEL HARRISON: We've been working with such an incredible team. It's such a multidisciplinary project and everyone's united around a common goal of really trying to help protect the Great Barrier Reef. We have a self-imposed rule that we don't do any research on Sea Country without the free, prior, and express consent of the Traditional Owners. Marine Cloud Brightening is absolutely not a replacement for cutting emissions. Our modelling shows really, really clearly that cloud brightening can help buy some time to achieve that and stabilize coral cover on the Great Barrier Reef. So the potential applications for this globally are huge. People are starting to think about whether you could use the same technology to save other ecosystems to help maintain ice in the poles. This research is really one of the few things that I've seen so far that I believe can give the Reef a chance into the future of still being there when my kids grow up to be old enough to experience that amazing world under the water that they're yet to see.