Ocean Antacids

An Interesting Short Run Solution

T. C. Brandon-Cooper

LAST TERM, I wrote at length about a lesser known impact of our use of fossil fuels: ocean acidification. Already, our oceans are 30% more acidic than they were 200 years ago and consequently, many marine organisms, especially those who rely on calcium carbonate, are struggling to survive. The impacts of ocean acidification are becoming so worrying that many scientists are predicting that some marine ecosystems, particularly coral reefs, will collapse in the near future. Is there a way we can fix this problem to save species and ecosystems?

The first and most obvious is to transition to renewable energy. The cause of ocean acidification is an increase in carbon dioxide in the atmosphere. Therefore, to slow down the rate of acidification, we need to slow down the amount of carbon dioxide being put into the atmosphere. Whilst this won’t return the ocean’s pH to what it was originally, it would slow down the rate of change allowing the biophysical environment to adapt to the new normal, making it an important action to take to protect our oceans.

However, some scientists have put forward another short term solution which aims to artificially protect marine ecosystems from rapid rises in pH. This short term solution is called Artificial Ocean Alkalinization or AOA and involves depositing large amounts of alkaline minerals into the ocean. This would increase the surface water’s total alkalinity, creating a buffer that would cause the oceans to resist increases in their acidity. AOA is therefore geoengineering, a project aimed at artificially interfering in the environment for positive effect.

AOA has proven to be somewhat effective on small patches of the southern Great Barrier Reef. However, the proposal for it to be used on a large scale is very risky. It would involve depositing large volumes of foreign minerals into the ocean with the deliberate purpose of altering the ocean’s chemical processes, raising many red flags…

However, there may be merit for AOA in trying to protect small patches of ecosystems which are on the brink of collapse as a result of ocean acidification, particularly coral reefs after tropical cyclones. Coral reefs find it much harder to rebuild in an acidified environment as the presence of calcium carbonate is decreased, therefore, during these times, AOA could be a solution.

There is no easy solution to ocean acidification. The only way out is to transition away from fossil fuels and towards renewable energy. The main driver for ocean acidification is carbon dioxide emissions and, while innovations like AOA might help in the short term, the only way to properly address this problem is by reducing our emissions.