What is going on here?
In an effort to mitigate the climate crisis, one company, CarbonRun, has proposed a way to trap carbon dioxide in the world’s rivers. In this method of carbon removal, carbon is ultimately stored indefinitely by the natural sponge-like abilities of the oceans. How? Simply by adding limestone to the water.
What does this mean?
Rivers act as a sort of circulation system for the planet, carrying carbon from decomposing materials and rock debris from the land to our oceans where the carbon then settles on the seabed to become part of the ocean floor. This effectively traps the carbon in the ocean for a long period of time. Since the carbon has never been released into the atmosphere, it can’t warm our planet and exacerbate the climate crisis.
However, carbon dioxide carried by rivers is constantly escaping into the atmosphere. To prevent this, CarbonRun is testing the theory of adding limestone to the river to make the carbon dioxide stay dissolved long enough to be swept out to sea
The process is called ocean alkalinisation. If you add an alkaline (like limestone) to the ocean (say, through the river systems) it causes a chemical disruption. This makes the ocean absorb even more carbon dioxide from the atmosphere to restore its equilibrium. Nature is pretty awesome.
Why should we care?
More and more we’re seeing a dual approach to solving the climate crisis. Firstly, by preventing more carbon dioxide from being emitted into our atmosphere; and secondly, by removing some of the carbon dioxide that is already in the atmosphere. Carbon removal presents a huge commercial opportunity – a fact represented by the investment fund Frontier, which is backed by USD$ 1 billion from giants like Alphabet and Stripe.
However, this solution is not all upside. There are always risks. While the ocean absorbs large amounts of carbon, if it absorbs too much then this process can lead to ocean acidification. As carbon dioxide dissolves in seawater, it gets more acidic, potentially impacting marine life. And perhaps the largest risk is the unknown. Scientists don’t know what the impact on wider ocean chemistry and marine ecosystems will be – especially at the local level. However, scientists are weighing this risk of the unknown against the benefits of mitigating the climate crisis.
Be curious!
- Read up on different types of methods to remove carbon already in our atmosphere.
- Listen to the Zero podcast which focuses on the technologies and solutions needed to fight the climate crisis!
- Looking for your next book to read? Consult this list of books which focus on climate solutions.
