A proportion of the billions of tonnes of carbon dioxide that we emit each year remains in the atmosphere, causing it to heat up but about a third of it is absorbed by the oceans, producing carbonic acid. Coral reefs and shellfish beds are dying and the lives of fish are threatened.
Scientists estimate that about one million tonnes of carbon dioxide is absorbed by the oceans every hour and as a result our seas are 30% more acidic than they were a century ago. Increased acidity affects the levels of calcium carbonate in the shells and skeletons of many sea creatures and also changes their reproductive cycles.
The oceans have been affected by acidification in prehistoric times but these occurrences happened at a much slower rate, enabling sediments to act as a cushion. Levels of carbon dioxide are rising much faster today and the surface seawater will be 150% more acidic than it was in 1800 by the end of the century. Millions of species of fish, shellfish and micro-organisms will not survive and there will be no richness or variety in the seas.
It is an unhappy picture; and it is not so distant in the future. We continue with our high carbon lifestyle even though we know that the damage that we are doing to the climate and the seas will soon be irrevocable. We need to take steps now to embrace a lifestyle that causes far fewer emissions of carbon dioxide and maybe we will be able to repair that damage.
