An emerging sector is striving to develop solutions to combat global warming by harnessing the oceans’ capacity to absorb pollutants and heat. Numerous companies and academic groups propose the concept of submerging rocks, nutrients, agricultural waste, or seaweed into the sea with the aim of storing harmful carbon dioxide for hundreds or even thousands of years. Almost 50 field experiments have been conducted over the past four years, with startups securing hundreds of millions of dollars in initial funding. Most businesses focusing on offshore climate solutions aim to decrease or alter the carbon dioxide stored in the ocean.
In an experiment conducted in Halifax Harbour, Nova Scotia, Planetary Technologies utilized magnesium oxide and added red dye to trace the flow. Upon being dissolved in seawater, it converts carbon dioxide from a gaseous state to stable molecules that remain inert in the atmosphere for millennia. According to Will Burt, the chief ocean scientist at the company Planetary Technologies, adding alkaline or basic minerals to the ocean functions similarly to an antacid neutralizing stomach acid.
Planetary’s tests thus far suggest that magnesium oxide poses minimal hazards to marine ecosystems, plankton, or fish. The mineral has been commonly used in water treatment plants and industrial facilities to de-acidify water. Limestone, olivine, and other alkaline rocks have identical effects. Other businesses focus on growing seaweed and algae, which absorb carbon dioxide from the ocean, similar to how trees absorb it from the air. Still, others view the ocean’s deepest parts as a site for storing organic matter that would emit greenhouse gases if left on land. However, the field remains plagued by disputes over the potential consequences for oceans if these strategies are implemented on a massive scale and the precise benefits for the climate.
David Ho, an oceanography professor at the University of Hawaii and co-founder of nonprofit [C]Worthy, which verifies the impact of ocean-based carbon removal, stated, “The current experiments and their scale are relatively safe. However, the question arises about what would happen if the scale were increased to billions of tons per year.” Ho added, “For this approach to be effective, carbon dioxide removal must transition from something most people are unfamiliar with to the largest human endeavor in a brief period; it’s intimidating.” He believes that scaling this up would require substantial resources, energy, and money, in the trillions of dollars annually.
Source: http://www.africanews.com/2025/03/22/ocean-carbon-solutions-face-growth-and-environmental-challenges/
