Riding the Wave of a 100 Year Problem: Ocean Acidification


Tired of hearing about global warming? I don’t think you’re alone. According to a Pew survey taken this fall, fewer Americans (35%) see global warming as a very serious problem (down from 44% in April 2008). Only 57% think there is solid evidence of warming (71% did in April 2008).

My hunch is that people are feeling fatigue from the daily dire environmental news and the fact that all the proposals on the table for CO2 emission reductions are nowhere near where we need to be to begin to halt (let alone reverse) environmental catastrophe. The U.N.-backed Intergovernmental Panel on Climate Change says developed countries would have to reduce greenhouse gas emissions by 25 to 40 percent below 1990 levels by 2020 to avoid runaway climate change. Lots of people think that binding agreements for those targets are unlikely.

The climate disaster we’re told is coming is just too much to think about, perhaps. It’s much easier to convince ourselves that it’s really not as bad as we think, hence those numbers in the Pew survey. (Add to that the immediate pressures of a recession and it’s even less of a surprise.)

But here’s another major reason we should stop burning dinosaurs:

This reason is even less disputed than global warming, and it is more rapidly approaching: Ocean Acidification. Scientists have only begun to uncover the full implications of ocean acidification for the past five years or so, and it’s only been in the news with any prominence this year. Most people still don’t know about it.

The oceans of the world act like a giant, watery carbon sponge, soaking up about one-fourth of all the carbon dioxide emitted by our fossil-fuel burning. As reported by The Guardian, that’s something like six million tons a day.

The carbon in the oceans causes the pH of the water to drop and the normally alkaline ocean becomes less so – in short, it becomes more acidic. Studies show that the pH of the world’s ocean has dropped about 0.1 pH units over the past several decades. If emissions continue at their present rate, scientists estimate that the pH will drop another 0.3 to 0.5 pH units by the year 2100.

What happens when the ocean pH decreases? It makes it more difficult for animals with hard outer shells like mollusks, corals, sea urchins and other tinier organisms to form their skeletal structures. It may also change the way these organisms breathe and reproduce. The chemical changes in sea water that accompany acidification can prevent their shells from forming and extremely altered water can actually eat away at already-formed shells.

This is a devastating situation for the entire food web. And I’m not just talking about oyster and scallop shortages. Higher predators like whales and salmon eat tiny shelled creatures called pteropods. If the pteropods can’t survive acidification, we can add starvation to the list of troubles that our fish stocks face, including overfishing, destructive fishing methods and good old-fashioned pollution.

All right, so it’s so long, fish – setting aside the ocean’s place in our ecosystem for a minute and thinking of it only as a source of food. We’ll still survive, right? We can just eat other things, but a great many people will not be so lucky. The very places where famine is already a problem are the places where people depend most heavily on seafood for their protein needs.

“Small island nations, already threatened by climate change via sea level rise, often depend entirely on seafood for their protein,” says Sarah Cooley, a Postdoctoral Investigator at Woods Hole Oceanographic Institution.

According to some sources, more than 1.5 billion people depend on fish for 20 percent of their average per capita intake of animal protein. Nearly 3.0 billion additional people depend on seafood for 15 percent their protein. In developing nations such as Indonesia, Bangladesh, and Ghana, people depend on fish for as much as 50 percent of total animal protein. These are the places that are already poised to be the most affected by the rising sea levels, drought and extreme weather patterns caused by climate change, so it’s likely that fish could become an even more important part of diets in these places as agricultural crop yields fall even further.

“Usually, the most vulnerable human communities are the ones that contributed least to climate change,” says Cooley. “This is true for ocean acidification also. Populations in tropical developing nations will swell in the next 50 years, but at the same time, ocean acidification plus global temperature rise will likely alter the coral reef ecosystems that provide subsistence fishermen with their dinners. Where will these people find their protein? This doesn’t even include the fact that as countries become wealthier, they eat more protein.”

Studies that predict increases in hunger due to overfishing do not even take into account the likely effects of ocean acidification because scientists are still determining how the problem will affect entire marine food chains. Other studies warn of devastating effects.

For the audio-visual learners among us, this 20 minute video narrated by Sigourney Weaver explains the whole process very well.

If the news alone weren’t troubling enough, you should also know that it’s impossible to reverse the existing acidification.

We must stop emitting so much CO2 now to avoid further damage.

The effects of acidification are already being seen. Knowing all we have at stake, it makes me sick to watch some of our lawmakers in action. Resisting climate change legislation over the worry that it will hurt coal state economies is completely irrelevant when we’re talking about the collapse of an entire ecosystem, possibly in our own lifetimes.

What can you do about it?

Pressure companies like Toyota to stop lobbying against clean energy and support those companies, like Apple Computers, that quit The Chamber of Commerce in protest of its retrograde climate legislation policies. When the final bill comes up for a vote, pressure your representatives to do the right thing. It may seem hopeless, but hopeless is not an option.

Image: Wonderlane

Vanessa Barrington

Vanessa Barrington is a San Francisco based writer and communications consultant specializing in environmental, social, and political issues in the food system.