Is seawater alkalinization an unproblematic way of carbon dioxide removal?

Maanantai 1.5.2023 klo 17:30 - Mikko Nikinmaa

It is simple. One just has ships floating in the high seas spreading alkaline substances to seawater. As a result, the pH of the seawater increases, carbon dioxide-bicarbonate-carbonate equilibrium is shifted to the right, and consequently carbon dioxide is mopped up. What a neat and cheap way of combatting climate change, and it can be done without any requirements for technological advancements. No wonder technology-oriented people have been jumping in excitement. But are there serious downsides?

The question becomes immediately relevant, as apart from the climate crisis we are experiencing biodiversity crisis. And any large-scale bioengineering project such as seawater alkalinization will affect the biota of the area which is alkalinized. It is not known how large the effects are, which species suffer from, and which don’t mind about the pH changes. So, if an alkalinization project is carried out, one is really doing a large-scale experiment with unknown results.

A recent modelling study about alkalinization of seawater and its possible effects has been reported in Environmental Research Letters (18: 044047;; Fakhraee et al.).

Kommentoi kirjoitusta. Avainsanat: climate change, carbon dioxide sink, geoengineering, seawater pH