Early-career ocean professionals evaluate Canadian marine carbon sink and emerging field of ocean carbon removal

Did you know the oceans play a huge part in slowing down the impact of climate change on the planet? The oceans absorb around 25 per cent of all fossil fuels emitted on Earth, acting as a sink for greenhouse gases like carbon dioxide. In fact, the ocean stores 50 times more carbon than the atmosphere, and 20 times more than land plants and soil combined.

The ocean can be a more durable storage solution, as some carbon removal processes in the ocean can hold carbon for hundreds or thousands of years, compared to decades for land-based storage like trees.

A perspectives paper written by a group of early career ocean professionals, including current and graduated University of Calgary students, summarizes the current research and identifies the steps forward to improve understanding of the marine carbon sink in Canadian national and offshore waters.

“A lot more people are probably familiar with terrestrial sinks, as everyone has an understanding of photosynthesis,” says Christina Braybrook, BSc’16, and a current PhD student in the Department of Geography.

“There are associated biological and chemical processes taking place in the ocean that also contribute to the exchange of carbon.”

The paper focused on Canada’s three major ocean basins, the Pacific, the Atlantic, and the Arctic, and aimed to bring light to the importance of the oceans’ role in net-zero carbon emissions.

“In order to meet our Paris Agreement goals, it’s going to take more than just emission reduction, but also us removing CO₂ from the atmosphere,” says Patrick Duke, BSc’16, MSc’19, and current University of Victoria PhD student.

Questions about oceans' ability to store carbon

Concerns do exist with the oceans' ability to store carbon, mainly that the reaction at the surface between air and water can cause the ocean to acidify, affecting the marine ecosystem.

There are also other factors to consider when looking at the ocean as a carbon sink, such as the ocean warming that might influence the capacity of our oceans to absorb more CO₂ from the atmosphere.

The main issue the authors encountered in the current research is there is no known baseline to tell that a difference is being made with an intervention.

“The ocean is so dynamic that if you introduce an intervention off the coast of B.C., the interaction with the atmosphere may take place in a completely different part of the ocean because the water is moving around,” explains Duke.

This leads to a lot of uncertainty to say whether any currently proposed carbon dioxide removal methods will make a big difference because of the natural variability of the oceans and the scale of intervention.

“Overall, it’s tough to tell what’s happening if you’re not taking measurements and improving models before you introduce interventions,” says Duke.

The paper found the current literature agrees that Canada’s oceans act as sinks for carbon, but the geographic boundaries of all the studies make it difficult to get a number for how much carbon the Canadian oceans are absorbing as a whole.

“To do that, we need more long-term monitoring in all three basins to come up with a more accurate number to go forward with solutions in the future,” says Mohamed Ahmed, PhD’20.

Indigenous groups' involvement critical to success

Another aspect the authors focused on was including Indigenous groups in the planning of carbon dioxide removal, as Indigenous communities along the coast will disproportionately require ocean acidification action plans and strategies to mitigate climate change impacts.

Carbon dioxide removal companies will approach Indigenous communities to evaluate project proposals on their land and their waterways.

“We feel that capacity-building in those spaces that is Indigenous-led and collaborative, with a lens of both western and Indigenous ways of knowing was really important,” says Duke.

The paper highlights projects and collaborative frameworks across Canada’s three ocean basins that were community specific. These successful programs had been suggested by Indigenous communities as scientific frameworks for collaboration that could align with the emerging ocean carbon space.

“We really advocated that academia and industry should align its values with those communities and collaborative frameworks in order for this to be successful and inclusive going forward,” says Duke.

Written from the perspective of grad students who do a lot of the work on these studies and projects, the writers found the fast and short nature of a graduate program make it impossible to build the relationships necessary to make those long-term solutions with Indigenous communities work.

“As much awareness needs to be spread to graduate students and faculty that this needs to become the norm because Indigenous communities are disproportionately affected by these consequences of climate change,” says Braybrook.

“We need to bring these communities on board, and not only have them on board, but leading these programs alongside researchers.”