Revisiting ocean acidification, food security and our earth system

Ocean acidification is a global issue, which is affecting all ocean regions. It is important as it may have severe impacts on marine organisms and ecosystems. Loss of biodiversity is a likely result, accompanied by a reduction of harvestable resources, including those associated with human food resources. If CO2 emissions continue at the same rate, ocean acidification will have a considerable influence on marine-based diets for billions of people worldwide. The only way to stop ocean acidification is to curb emissions of CO2.
The ocean will not be healthy once we stop emitting carbon. Instead, the CO2 that we have emitted in the last 200 years will still be taken up by the oceans in the future. It will take thousands of years to recover, as ocean acidification is only neutralized by the very slow weathering of rocks or dissolution of sediments releasing carbonate ions to the oceans. Nevertheless, reducing emissions of CO2 to the atmosphere is the most efficient way of stopping ocean acidification. Importantly, some geoengineering measures aim to only cool the Earth under growing CO2. These will not stop ocean acidification, as it is the increasing atmospheric CO2 that causes ocean uptake and acidification.