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Ocean Acidification

It’s really not that complicated. You know that the fizzy drinks you consume are ‘carbonated’. They are infused with carbon dioxide, which makes the bubbles. They are also acidic – again, you know that consuming too much fizzy drink rots our teeth. This is because of the carbonic acid that is created when we force carbon dioxide into water.

In exactly the same way, the ocean absorbs carbon dioxide and acid is created. The reason the ocean is not acidic already, is because the acid is locked away in the bodies of sea creatures that absorb it. The ocean acts as a ‘buffer’ against increasing acidity. Unfortunately, there is a limit to the oceans ability to act as a buffer and now, the level of acidity is increasing significantly. Our oceans have recently become about 0.2 points of pH (a measure of acidity) more acidic. This may not seem a lot but that’s because it is measured on something known as a ‘log scale’. Each point is in fact 10 times bigger than the next, so the real increase is about 30%. This is unprecedented in 12 million years.

Back to the rotting teeth analogy. Marine animals ‘calcify’ their skeletons in the same way we do, by absorbing calcium carbonate. So their skeletons can be weakened by acidity. Also, as acidity increases, it becomes more and more difficult to even find the carbonate needed to create bones. As it dissolves in water, it becomes less available. Limestone is also calcium carbonate and is the same material with which we make cement to bind our houses, roads and skyscrapers. Twenty years ago in Europe, the facades of old limestone buildings from hundreds of years back started to dissolve, because the burning of sulphurous brown coal causing acid rain. Although this is a different chemical, the principle is the same. Rain is naturally slightly acidic because of carbonic acid. Acid rain is still a problem today in built up areas with significant traffic levels. So, the role of fossil fuels and their relationship to global acidity is not a new phenomenon at all.

As humans, our blood chemistry is acutely balanced with our environment. If it changes, even slightly, then we cannot absorb crucial minerals and we die. Ocean creatures are bathed in seawater and changing its chemistry is equally fraught.

‘Ocean Acidification’ as it is known, is a very serious and impending problem. It’s not the same as climate change but it is a consequence of our carbon lifestyles. The latest research from the Southern Ocean, which absorbs the vast majority of our global carbon, is that a ‘tipping point’ may be reached within 30-40 years. This means that many of us may live to see a world that changes so abruptly that our children may not have the privilege to enjoy the natural wonders of the world that we take for granted.

It’s not too late to do something if we act fast but we must act now!