The ocean stores 90% of the Earth’s CO₂
This is due to alkalinity, which, in short, can be defined as the ocean’s capacity to neutralize acid. A higher ocean alkalinity content leads to a higher CO₂ storage capacity of the seawater. This knowledge is especially important now that the CO₂ concentration in the atmosphere is rising rapidly.
Natural processes in the ocean produce alkalinity and increase the seawater’s uptake of CO₂ from the atmosphere. Using some of these natural processes as inspiration, new technologies for ocean alkalinization – active addition of alkalinity to the seawater for capturing and storing CO₂ – are being developed.
Coastal Carbon aims to advance research on natural sources of ocean alkalinity and investigate options to enhance ocean CO₂ uptake and storage
What are the main processes driving natural alkalinity release in the ocean?
The ocean is a crucial regulator of the atmospheric CO₂ concentrations as it absorbs 30% of all CO₂ emissions and stores more than 90% of the Earth’s CO₂. The alkalinity concentration in the ocean determines the long-term CO₂ storage capacity, as alkalinity fixes CO₂ so that it cannot be returned to the atmosphere.
A better understanding of the processes that naturally release alkalinity will allow us to protect and restore marine areas that are important for the ocean’s CO₂ storage.
Can we enhance ocean CO₂ uptake by increasing ocean alkalinity?
The weathering of rocks and shells naturally releases alkalinity. These processes drive the ocean’s CO₂ uptake on geologic timescales. However, if these natural processes could be accelerated, causing the ocean’s alkalinity concentrations to increase more rapidly, the ocean’s CO₂ uptake and storage capacity could increase.
Coastal Carbon is exploring the possibility of speeding up weathering in the ocean and is investigating the effects of these processes on the natural system.
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