I am Dr. Elizabeth Shaik. I'm a chemical oceanographer and my research is focused on observing and understanding the ways in which the ocean exchanges carbon dioxide or CO2 with the atmosphere. Net removal of carbon dioxide from the atmosphere requires both capturing it, getting it out of the atmosphere, and also storing it somewhere over long periods of time.

And the ocean has emerged as one of the feasible places where we could potentially store additional CO2 over long time periods. The ocean is by far the largest reservoir of carbon on the planet. In the present day. It already contains some 45 times more carbon dioxide than what is currently in the atmosphere.

Rocks are input to the ocean and those allow the waters to become more basic or more alkaline, which induces an uptake of CO2 from the atmosphere. And in fact, it's this process that occurs naturally in the ocean and allows CO2 to move from the atmospheric reservoir into the deep ocean where it stays in a stable form for tens of thousands of years.

If we wait long enough, the majority of anthropogenic CO2 that found its way into the atmosphere from human activities, the burning of fossil fuels, deforestation, cement production and so on will ultimately end up in the ocean through natural processes. 

We would like to find technologies and strategies that allow us to forcefully accelerate the process of moving the CO2 into the ocean.

We are focusing on studying something called Ocean alkalinity addition, which is adding. alkalinity or a basic material to the ocean to induce an additional uptake of CO2 from the atmosphere. 

What we're interested in doing is what we call electrochemical approaches, and that involves a first step of taking sea water and splitting it into its acidic and basic components.

That would be hydrochloric acid as the acid and sodium hydroxide as the base, and then reintroducing the basic component back to the ocean. The way that we will track this modified stream of seawater is using state of the art sensors, Some of which are being developed by our team and also really sophisticated bio geochemical, ocean models.

I am Rich Mather. I'm a climate scientist. Working at CSIRO, I've spent about three decades modelling the climate system with a particular focus on the oceans and the role of the oceans in the climates and carbon cycle. 

With models, we can actually do this ocean Alkalinity addition. We can track how it behaves in the ocean, and we can also quantify how it's taking up carbon dioxide from the atmosphere.

The models provide a nice kind of toolkit to first start that exploration. And we've done that at global scales and as we push forward with this particular project, we'd like to do that at much more local and regional scales. This research is providing the fundamental science that allows us to make a critical assessment, whether this is a good idea or not, 

Can we have an effective way of removing carbon dioxide from the atmosphere? Can we do it in a way that actually doesn't have any detrimental impacts on the biology of the ocean or the chemistry of the ocean? 

The idea that we should not tinker with the ocean is a really understandable, and earlier in my own career, I shared some of those reservations. 

Now that the problem has become so much more urgent and we're beyond the place where we can just rely on moving away from emissions, we really need to do net removal as well. 

I think one way of helping people to understand the urgency is to think of the natural experiment that we're already participating in, which is the release of fossil fuel emissions to the atmosphere.

One could argue that's the biggest geoengineering experiment we have going, and what we're talking about would actually help to reset the ocean to its pre-industrial conditions. 

My hope is that the need for action outweighs the reluctance to tinker. 

But first of course, we need to show that we can do these things without causing harm, and we need to show that we can do these things in a safe and transparent way.