The ocean is the largest carbon reservoir on Earth, currently holding approximately 45 times more carbon dioxide (CO2) than the atmosphere. Naturally, rocks on land weather and dissolve, flowing into the ocean to make the water more alkaline (basic). This alkalinity induces a chemical reaction that pulls CO2 from the atmosphere into the water, eventually sinking it into the deep ocean where it remains stable for tens of thousands of years. While anthropogenic (human-created) CO2 will eventually end up in the ocean through these natural cycles, the process is too slow to mitigate the immediate impacts of climate change. Scientists are now investigating ways to forcefully accelerate this natural absorption capacity.
Australian government and scientific research bodies provide extensive data on the global carbon cycle and the ocean's role as a carbon sink.
Ocean Alkalinity Enhancement (OAE) is a proposed technology designed to speed up carbon removal. The specific approach discussed involves electrochemical processes. Scientists take seawater and split it into its acidic and basic components—specifically hydrochloric acid and sodium hydroxide. The basic component (sodium hydroxide) is then reintroduced into the ocean. This addition increases the alkalinity of the seawater, which chemically allows it to absorb more CO2 from the atmosphere. To ensure safety and verify results, this modified seawater is tracked using state-of-the-art sensors and sophisticated bio-geochemical models to monitor chemical changes.
Leading Australian scientific institutions publish reports and research summaries regarding emerging carbon dioxide removal technologies.
Before deploying OAE at a large scale, scientists like those at CSIRO use complex computer models to simulate how added alkalinity behaves in the ocean and how much CO2 it captures. These models help researchers scale up from global estimates to local and regional predictions. A critical part of this research is risk assessment: ensuring that 'tinkering' with ocean chemistry does not harm marine biology. The lesson highlights an ethical shift; while many scientists were previously reluctant to engineer the climate, the urgency of the climate crisis implies that net removal of CO2 is now necessary alongside emissions reductions. The current release of fossil fuels is framed as an uncontrolled geoengineering experiment, whereas OAE aims to safely reset the ocean to pre-industrial conditions.
Climate research organizations in Australia offer resources on climate modelling and the ethical debates surrounding geoengineering.