The organizers of the 4th The Ocean in a High-CO2 World symposium asked me to write an OpEd piece for the Sydney Morning Herald.
The challenge was to write about ocean acidification in a scientifically accurate way but also in a way that would be understandable to the average reader of the newspaper. Also, I wanted to write something that the average person could relate to — to humanize the issue so it wouldn’t seem so abstract.
Furthermore, it being an editorial, I was encouraged to put forward my own political views in some sort of general way, but I wanted to be general enough that the conference organizers and attendees would feel comfortable with what I was saying.
Also, I wanted to avoid being overly depressing or disingenuously hopeful.
Further, I wanted it to have some structure and literary value — something I think I achieved in some parts but not in others. On top of all of this, I am trying to do too many things, so the piece had to be more-or-less written as a stream-of-consciousness, because I didn’t have time for wordsmithing.
The headline for the OpEd piece was from the editors at the Sydney Morning Herald, and was not my concoction.
Anyway, resisting the temptation to fine tune post-publication, here is what I came up with. (This is a first draft, except for correction of minor grammatical errors. There is a ‘the’ that should have been removed from the last paragraph. Both the word ‘real’ in the first paragraph and the ‘for it’ after ‘life and death’ should have probably been eliminated.)
Oceans bearing the brunt of relentless carbon emission
by Ken Caldeira (published in the Sydney Morning Herald, 2 May 2016)
Most people live on land where the oceans are little more than a blue expanse of imagination. Does what I do right here on my spot of dry earth really matter to the far away vastness of the real ocean?
On a cold morning, when my home heater kicks on, natural gas burns and a plume of carbon dioxide streams out of my chimney and into the sky. When I make my morning toast, there is a power plant somewhere providing electricity to my toaster that is burning gas or coal and releasing giant plumes of carbon dioxide into the air. Much of this CO₂ will remain in the atmosphere for many thousands of years.
This pollution has physical consequences for our climate system, but it also has chemical consequences for our oceans.
In the atmosphere, too much CO₂ can make the world uncomfortably warm and melt the giant ice sheets and so on. Bad stuff.
This year has been just about the worst ever for coral bleaching. CO₂ in the atmosphere has been making Earth hotter and this is causing coral reefs to bleach, causing many colonies to die.
Most of the carbon dioxide we release to the atmosphere will eventually be absorbed by the oceans. They have already absorbed about one-quarter of the CO₂ produced by industrial civilisation over the past couple of centuries, and this process is making them more acidic.
When CO₂ reacts with seawater, it forms an acid. In high enough concentrations, this acid can corrode shells and skeletons of many marine organisms. In lower concentrations, it can make it harder for an organism to produce its shell or skeleton, and this could in some cases tip the balance between life and death for it.
There has been plenty of carbon dioxide in the atmosphere in the ancient past, and corals and clams and so on did just fine. There are natural processes involving rivers and sediments that buffer ocean chemistry over periods of thousands or tens of thousands of years. But right now, the ocean chemistry is changing way too fast to be buffered by Earth’s natural cycles.
The problem for marine organisms isn’t so much where we are going but how fast we are getting there. If we would spread out the emissions over tens of thousands of years instead of a few centuries, natural cycles would buffer the effects on ocean chemistry and there would be little to worry about. But if we do not dramatically reduce our rate of CO₂ emission, we will make the biggest and most rapid change in ocean chemistry the world has seen in many tens of millions of years – long before there were any humans on this planet.
We recently conducted experimental work in the Great Barrier Reef, providing evidence that ocean acidification is already slowing growth of the coral reef we examined. Increased stress from ocean acidification is probably making corals less able to stand up to heat stress and so contributing to coral bleaching. We have also made careful observations of tide pools along California’s coast, and the organisms there also seem to be affected by changes in ocean chemistry.
As a scientist, I work to better understand the relationships between our actions and what happens in the real world. On a chilly morning, I heat my home and make myself some toast and coffee, and sink into my easychair. I understand that in doing this I am contributing to killing off coral reefs and that I am affecting other marine ecosystems in unimagined ways. We know that protecting the oceans means we need, among other things, to stop using the atmosphere as a waste dump for our carbon dioxide pollution. We need to stop building things with smokestacks or tailpipes.
Scientific understanding is the cornerstone of good public policy. Science can never tell us what to do, but it can give us an idea of what might happen if we choose different courses of action. An intensified effort to develop the scientific knowledge can help us better understand the consequences of our choices. And we, as a society, can choose wisely.