As global efforts to combat climate change intensify,innovative carbon capture techniques are gaining traction. In Nova Scotia, scientists and startups are pioneering methods to enhance the ocean’s natural ability to absorb carbon dioxide, experimenting with mineral additives in both marine and freshwater environments. These localized initiatives, detailed in a report by Dominique Forget airing on ICI TÉLÉ’s Découverte program, represent a possibly significant – though still experimental – approach to mitigating the effects of rising global temperatures and ocean acidification.
Halifax, Nova Scotia – A growing movement to combat climate change is taking root in the industrial port of Halifax, where scientists are exploring innovative ways to enhance the ocean’s natural ability to absorb carbon dioxide. As global temperatures continue to rise and international efforts to curb emissions face challenges, these local initiatives offer a potentially significant, though still experimental, approach to carbon capture.
Oceanographer and chemist Will Burt, working with the startup Planetary Technologies, believes a simple solution could revolutionize climate action: injecting a mineral powder into the wastewater of a local power plant before it flows into the sea. The goal is to alter the water’s chemistry, effectively turning the ocean into a more efficient “sponge” for absorbing CO2.
“It’s such a simple idea,” Burt said. “Why didn’t I think of it before?”
Will Burt is an oceanographic chemist and works for the startup Planetary Tech.
Photo : Radio-Canada / Sylvie Mallard
Oceans naturally absorb a significant portion of the CO2 released into the atmosphere, but this process comes at a cost. As CO2 reacts with seawater, it lowers the pH level, leading to ocean acidification, a threat to marine ecosystems.
Planetary Technologies has been adding a powder of magnesium hydroxide to the wastewater from the Tufts Cove power plant for the past two years. “When you add it to seawater, it neutralizes the CO2,” Burt explained.
The magnesium hydroxide works in reverse of acidification, increasing the water’s pH and forcing some of the dissolved CO2 to transform into bicarbonate, a stable and non-toxic molecule. “This bicarbonate dissolves in the ocean like sugar in your coffee,” Burt illustrated.
This process creates a “drawdown” effect, allowing the ocean to capture more greenhouse gases from the atmosphere once the CO2 is removed from the water.
Limestone in River Systems
Less than two hours from Halifax, another company is employing a similar approach, but in a different environment: rivers. Carbon Run, co-founded by biologist Eddie Halfyard and Dalhousie University biogeochemistry professor Shannon Sterling, utilizes crushed limestone to counteract acidification in waterways.
Carbon Run, co-founded by biologist Eddie Halfyard and Dalhousie University biogeochemistry professor Shannon Sterling, uses crushed limestone to neutralize acidity in waterways.
Photo : Radio-Canada / Sylvie Mallard
Their first “doser,” located along the West River in Pictou, precisely injects limestone powder into the water. Like magnesium hydroxide, limestone is an alkaline mineral.
This practice isn’t new. As early as the 1970s, government and environmental organizations began adding alkaline minerals to rivers in Norway, Sweden, and Nova Scotia, aiming to neutralize acid rain, which had decimated salmon populations, as Eddie Halfyard, a passionate fisherman turned scientist, observed. “I’m a fisherman first, a scientist second,” he said.
By increasing the river’s pH, the limestone transforms CO2 into bicarbonate, creating the same drawdown and carbon capture effect seen in the ocean.
The Carbon Run team carefully monitors the river to ensure the powder dissolves properly and doesn’t accumulate on the riverbed, potentially harming fish eggs and invertebrates.
The project benefits from local support. Donald Rutledge, a resident of Sheet Harbour, has witnessed the return of salmon to his river after a conservation association installed a doser decades ago. “It’s thanks to the limestone, I’m convinced,” he stated.
Efficacy and Safety Concerns
While promising, these technologies raise concerns about their environmental impact. To verify the efficacy and safety of its process, Planetary Technologies commissioned a team of researchers from Dalhousie University to conduct an independent study.
Oceanographic chemist Dariia Atamanchuk is part of that team. For the past two years, she has been taking measurements and attempting to calculate how much greenhouse gas is captured through Planetary Technologies’ operations. She doesn’t yet have all the answers, but sees encouraging signs. Data shows an increase in alkalinity and carbonates in the water, confirming that the process is influencing the chemistry in the harbor waters.
Dariia Atamanchuk is an oceanographic chemist.
Photo : Radio-Canada / Sylvie Mallard
Other researchers are tracking the operations’ impact on aquatic life. Dariia Atamanchuk is reassuring from the outset. “When you add alkaline minerals to the ocean, you’re just mimicking a natural process, that of rock weathering and dissolving into the sea,” she said.
In Cornwall, England, Planetary Technologies faced public opposition and had to halt its operations. But in Halifax, the project benefits from a climate of trust. “The port of Halifax is an ideal location to conduct these trials,” Dariia Atamanchuk said. “It’s an industrial port and not a marine protected area with pristine ecosystems. Plus, everyone can see what’s happening. It’s done transparently.”
Reducing Emissions at All Costs
The urgency of the situation is driving these scientists. Shannon Sterling left her position as a professor at Dalhousie University to found Carbon Run, believing she would be more effective by directly tackling the climate crisis.
My course was so depressing. Every year, we have more data showing that we’re not succeeding in reversing the harm we’re doing to the planet. But now, there’s this new approach and we can mitigate climate change.
To finance their activities, Carbon Run and Planetary Technologies are relying on the sale of carbon credits to companies looking to offset their greenhouse gas emissions. The Frontier fund, which includes retail giants like Google, Shopify, and H&M, has already committed $25 million to Carbon Run and $31 million to Planetary Technologies.
However, scientists agree on one crucial point: enhancing alkalinity is only part of the solution. “We absolutely must reduce emissions at the source,” Shannon Sterling insisted. “Carbon capture should be used to absorb pollution that has already been released.”
Will Burt echoes this sentiment, stating that reducing emissions accounts for 90% of the work in combating climate change, while carbon capture represents the remaining 10%. “It’s like taking out the trash,” he illustrated. “You can reduce the amount of waste you produce, but you also have to collect what has already accumulated.”
Research continues to evaluate the full potential and long-term safety of these technologies. But, according to Will Burt, there’s no longer the luxury of waiting. “All solutions involve risk, he admits, but the risk of not acting is certainly much higher.”
The report by Dominique Forget will air on the Découverte program on ICI TÉLÉ.
