Episode 1 transcripts
Transcript of Prof. Shaun Fitzgerald interview
So cloud brightening is an interesting and potentially very helpful thing to consider for shielding more of the Earth from incoming solar radiation. So when clouds form over the ocean, they do so, let's say, in the first 1,000 metres above the sea. And those clouds provide two effects. The first is that then any sun that's shining on top of those clouds, more of it is reflected back to space rather than impacting the ocean. So they can actually protect the Earth in terms of a reflective property. The other property is that clouds also act as an insulator. So clouds provide these two fundamental processes. Cloud brightening is an idea whereby if you can create those clouds that were going to form anyway, but have them comprised of more smaller droplets rather than fewer larger ones, the ones that are comprised of more smaller droplets are optically whiter. If they are whiter, they will reflect more of the sun's radiation.
So the big question is, how might you be able to get clouds that are going to be formed of more smaller droplets? And the way to do that, potentially, is to create more sea spray. And when the sea spray evaporates, you're left behind with crystals of sodium chloride that get convected up naturally by convection currents. And those crystals of sodium chloride will act as cloud condensation nuclei.
And in fact, that's how clouds form over the ocean anyway. But the game afoot, therefore, is can you create more of those cloud condensation nuclei by using sprayers in order to make the clouds ultimately whiter?
Transcript of Prof. Daniel Harrison interview
We first started working on the concept of marine cloud brightening for the Great Barrier Reef after the mass bleaching events in 2016 and 2017 devastated large parts of the Great Barrier Reef and some estimates at the time were that up to half the coral had been wiped out in these two events. So we started looking at different ideas how we might be able to cool the ocean down and relieve some of the heat stress on the corals and when we did the calculations looking at lots of different ideas marine cloud brightening kept sort of floating to the top of the pile because the energetic leverage is so high.
So over the last five years we've been conducting field work over the Great Barrier Reef experimenting whether the 30 years of theory behind marine cloud brightening actually works the same way in practice as scientists have thought and we're up to the point of we've been gradually escalating the field experiments in conjunction with the federal regulator the Great Barrier Reef Marine Park Authority and developing the technology at the same time to make a bigger and bigger atomization of seawater and we're up to the point now where we can start to look at the effects on clouds in real time of these extra seawater droplets that we're putting into the atmosphere.
Globally we've been inadvertently conducting marine cloud brightening for decades. At the same time that we've been releasing greenhouse gases and warming up the atmosphere, ships traversing the remote oceans have been burning fuels and releasing sulfur compounds which also form cloud condensation nuclei. And so for decades we've been adding these extra cloud condensation nuclei into the atmosphere which has been brightening clouds and masking some of the effects of global warming. However in 2020 the International Maritime Organization brought in new rules limiting the amount of sulfur in ship fuels and so this was an effort to clean up air pollution in port cities where many ships congregate and the exhaust is concentrated and creates an air pollution problem. But an unintended side effect of these new rules is that now we're brightening clouds over the remote oceans much less and so this is amplifying the effects of global warming and some estimates are that this decade we will have doubled the rate of warming because of this dimming of the clouds.
Transcript of Nikki Baxendale interview
I've always been interested in the ocean and water - in fact I grew up in a chemistry lab, my father was a chemistry professor and so I spent a lot of time underneath the electron microscope and so macro patterns have always been a fascination to me and I love the way light changes an object by going through the water.
So this painting is called Stealth and it's about an orca gliding underneath the ocean and it's the light refracting through the surface and it displaces the imagery and the colour palette as it goes through the water. This is taken from a series that was shot in the high Arctic around Svalbard on an expedition I did with a small group of photographers and we were looking at the carving glaciers, the polar bear lifestyle and the whales in the Arctic.