An Idiot’s Guide To Ocean Acidification

Words by: Jonathon Davidson

I want to be as unbiased as possible in writing about the rising acidity of the world’s seawater and stay away from sounding ‘environmental activism-y.’ But in an article on what is effectively the lesser known and equally alarming sister of climate change, that’s a pretty hard thing to do. So, just a disclaimer: I’m not a hippie, I think Peter Garrett is a sell-out for reasons not related to Midnight Oil, and I don’t know if I want to vote for the Greens.

So What Is Ocean Acidity Then?

Ocean Acification is a fairly recent concept and field of study for marine biologists and oceanographers alike. The term was first coined in academic circles
only in 2003. Here is a definition, written by me, especially for this article:

Ocean Acidification.
verb. All of the water in the ocean becoming too dang corrosive for life to exist.

That’s pretty much it in a nutshell.

How Corrosive?

Not enough to melt your bones or anything, but enough that it’s already screwing with wild coral populations everywhere in a majorly bad way. In some spots around the globe, certain species of seashells are dying off due to being dissolved by the acid in seawater at a rate apparently not seen for millions and millions of years, according to deep-sea core samples analyzed in the last few decades.

Fun Fact: according to the aptly named documentary series Death Of The Oceans – at least it gets to the point – David Attenborough tells us that a majority of the world’s coral is likely to die off in our lifetime. Particularly at risk of future harm and current ongoing destruction is the Great Barrier Reef, of which great swathes have lost colour and become unhealthy and brittle, almost ghostlike.

What’s Causing It? Is It Carbon Emissions? It’s Carbon, Isn’t It?

Yep, it’s carbon. Also not helping is industrial runoff from ports all around the world, and sewers upon sewers worth of the soapy and pharmaceutical-ridden slurry that is human civilization’s collective septic tanks. Emissions go out, linger in the air, fuck up the ozone layer, raise the global temperature, mess with weather patterns, and also get absorbed directly into the ocean. Nobody wins.

You Mentioned Core Samples…How Do We Know This Isn’t Normal?

The acidity of the ocean sat at 8.2 for at least one hundred million years, it is thought. So, there’s an observable spike in the data: in the last 40 years, there’s been a dramatic drop in the pH levels of seawater everywhere.

What doesn’t do the issue justice is that the issue – and it’s real – lies in a 0.1 drop on the pH scale.

What Is A pH Level?

pH is basically the ‘degrees celcius’ of acidity. There is a scale which runs from 1 – highly acidic, coloured red – to 14 – not acidic at all, known as an ‘alkaline.’ Alkaline is purple: the dyes that react with acids in standard pH testing kits available in pharmacies all around the world all work to that same colour code.

So, right now the general pH of the ocean is 8.1, down from 8.2, where it has sat for millions of years. As I said, not melting bones or anything. But this represents a ~25% increase in ocean acidity in the last 200 years. 200 years, compared to the usual rate of “millions” that the earth takes to change, is basically like the split-second instance of a gunshot to the stomach. This is how we know it isn’t normal – there is a direct link between population growth and per capita energy usage and the dropping pH of the ocean (as well as the larger effects of climate change).

A Change Of 0.1 Doesn’t Sound Like That Much, Though…

That’s because the human brain is fucked and bad at dealing with big numbers and small numbers at the same time.

The ocean, according to howstuffworks, has 326 million trillion gallons of water in it. So, if we had 1 litre of water in a bucket that sat in some floating space throughout human history, and we realised that the water in this bucket dropped 0.1 in pH as it was increased to more and more pollution in the air and whatever, we’d probably reasonably accept that as being plausible. But once the bucket is the ocean, it seems sort of hard to grasp. The ocean is huge, seemingly endless.

But this change in pH, this descent on the scale to 8.1, is massive, if you think of it like pollution in the air changing the acidity in the water of all three hundred and twenty six million trillion of those 1-litre buckets. Every last one has been affected. 

So How Acidic Is Too Acidic?

8.0. That is the pH of the ocean at which seafood becomes a rarity, corals and anenomes become largely extinct, and we start witnessing the mass death of species all around the world while a few others will dominate and thrive in the altered conditions, effectively throwing ecosystems everywhere out of whack and forever altering the trajectory of humanity’s agricultural industry.

If the pH of the ocean further drops to 7.8, maybe even 7.9, literally everything in the ocean dies. We can’t know, and are probably going to find out.


Yeah. It’s accelerating, and there’s not a whole lot being done about it. Research is being done everywhere, new methods of prevention and education are under development (check out Death of the Oceans) and it is slowly making its way onto the agendas of policymakers and their electorates around the world in varying degrees.

However, preventive plans of attack are coming by too slowly, and it is unlikely that we will be able to revert impending damages and species loss predicted in the upcoming decades. The point of no return has been passed, is the general point to most of the current research. How we act now is important as societies and individuals alike, for the dying off the world’s coral, as well as possible larger changes, are almost definitely set to occur in the lifetimes of contemporary millennials. We may be alive when coral goes extinct. Let that idea digest for a moment.

The way to think about it is by keeping the law of accelerating returns in mind – as the human population continues to increase, expected to “plateua” at around 12 billion – roughly 5 billion too many as it is – the pH of the ocean is likely to drop further and further at a faster rate under the weight of human impact.

Recommended further reading here.