New industry aims to capture carbon through ocean methods

Many companies and researchers are working on ways to use the ocean to help reduce global warming. They believe that materials like rocks, seaweed, and crop waste can help capture carbon dioxide from the air and store it in the ocean. Over the past four years, nearly 50 tests of these ideas have been conducted. Startups have raised significant funds, but experts warn that the effects on ocean health and climate are still uncertain. Most climate models indicate that just cutting down greenhouse gas emissions won’t be enough. The world also needs to remove gases from the atmosphere. Projects on land, like pumping carbon from the air and creating underground storage, can be limited by space and local community impacts. Oceans, which already absorb heat and carbon, offer a potential solution due to their vast area. Some companies want to enhance the ocean's ability to capture carbon. They are researching how to change the form of carbon dioxide in seawater. Using materials like magnesium oxide, they hope to create a "vacuum" effect that draws in more carbon. Others focus on cultivating seaweed, which can absorb carbon dioxide in a similar way to trees on land. There are also ideas to bury organic material in the deep sea to prevent it from releasing gases if left on land. Funding for these ocean projects often comes from selling carbon credits, which represent one ton of carbon removed from the air. Last year, sales of marine carbon credits increased dramatically, but this amount is still small compared to what scientists say is needed for the planet’s future. Reactions from coastal communities have been mixed. Some residents are concerned about the potential impacts of these projects. Research suggests that people might not support large-scale climate engineering efforts. Scientists face several challenges as they study ocean carbon capture. The ocean environment is unpredictable, and added materials can be difficult to track as they may sink or wash away. Additionally, there are concerns about how long carbon can remain stored before being released back into the atmosphere. Scaling these projects to a level that can significantly impact climate change will require enormous resources and energy. For example, estimates suggest that a massive amount of seaweed must be cultivated along two-thirds of coastlines to effectively help combat global warming. Companies are exploring ambitious plans, including vast seaweed farms. Despite the risks and challenges, some experts believe that not trying these ocean solutions could lead to worsening climate change. The debate continues as research on this evolving field unfolds.