The oceans are a massive reservoir of carbon, and currently take up 25-30% of human-caused emissions every year.
The reason the oceans can store so much carbon is because they are alkaline. It is this naturally occurring alkalinity that makes seawater more basic (at a higher pH than freshwater), and allows it to soak up extra carbon dioxide from the atmosphere. Oceanic carbon is stored as dissolved bicarbonate – essentially dissolved baking soda – thanks to the natural weathering processes that enhance ocean alkalinity on geological timescales. The ocean carbon reservoir holds 15-20x more carbon than all land plants and soils combined.
Due to continued fossil fuel emissions, our climate is changing. These changes are no longer abstract: they are being felt by everyone all over the planet, today. Getting ourselves out of the climate crisis is perhaps one of society’s greatest challenges. Recent publications by the United Nations and the National Academies of Sciences have stressed that we must drastically reduce our carbon emissions and transition to more renewable forms of energy. In addition, avoiding the worst effects of climate change involve actively removing carbon dioxide (CO2) from the atmosphere, a process known as carbon dioxide removal (CDR). These CDR activities are not a silver bullet, and will not benefit the climate if they are not paired with substantial emissions reductions.
OAE may be durable, but monitoring is a challenge. The community of OAE practitioners has little experience deploying and tracking alkalinity plumes in the ocean, and we lack proven methodologies for quantifying the carbon stored by OAE. These methodologies will be crucial for the monitoring, reporting, and verification (MRV) of OAE technologies, and are important for unlocking their sequestration potential. We will deploy state-of-the-art equipment and instrumentation to measure and monitor alkalinity enhancement and the subsequent uptake of CO2 from the atmosphere.
Alkalinity addition offsets ocean acidification, but the ecological impacts of large and/or sustained OAE are unknown. The effects of OAE on marine ecosystems during real-world deployments have not been evaluated. While these effects are predicted to be either mild or positive, they must be documented and quantified. We will directly monitor primary productivity and the microbial community during our field experiments to establish the biological impacts of OAE.