Scientists warn ocean geoengineering could devastate marine life while fighting climate change

As climate catastrophes intensify worldwide, some researchers are turning to controversial geoengineering technologies that could artificially cool the planet or capture carbon from the atmosphere. With political action on fossil fuel reduction moving too slowly, these “science fiction-sounding” interventions are gaining serious scientific attention—particularly those targeting the world’s oceans.

A new study published in Reviews of Geophysics examines eight promising ocean-based geoengineering methods, including marine carbon dioxide storage (mCDR) and technologies that reflect sunlight back into space above ocean surfaces. The oceans already absorb about 25% of human-caused carbon emissions, making them an attractive target for climate intervention. However, lead researcher Kelsey Roberts from the University of Massachusetts Dartmouth warns that scaling up these untested technologies could have devastating consequences for marine ecosystems.

The research team identified significant knowledge gaps about how these interventions might affect ocean food chains, from microscopic organisms to whales and other megafauna. “If we implement some of these technologies, what would happen to the fish? What would happen to the megafauna?” Roberts asks, emphasizing concerns about global food security that depends on healthy ocean ecosystems.

While geoengineering might buy humanity crucial time to transition away from fossil fuels, the study highlights the urgent need to understand potential marine ecosystem risks before any large-scale deployment. The research underscores a troubling dilemma: the same oceans that could help solve our climate crisis might pay a devastating ecological price in the process.