You’re no doubt familiar with the ongoing and highly contentious political debate on the connection between carbon dioxide (CO2) emissions and climate change. But as we battle over greenhouse gases in the air, we overlook an equally serious problem: the increasing acidity of our oceans.
Little known by the public, the impact of CO2 emissions on our oceans is called ocean acidification.
Not all of the carbon dioxide emitted by human industrial activities remains in the atmosphere. In fact, about one-third of the CO2 released as a result of the burning of fossil fuels (like coal, oil and natural gas) currently ends up in the ocean. The ocean is the largest natural carbon sink on Earth; in other words, it acts as a reservoir, accumulating and storing carbon. This reduces the CO2 build-up in our atmosphere, but it also comes at a considerable price.
As ocean waters absorb CO2, the water becomes more acidic. The acidity of global surface waters has increased by 30 percent over the course of the last two centuries—a rather staggering figure—and this rate of acidification is only expected to accelerate. This doesn’t mean that the oceans will become acid. What it means is that there may be catastrophic impacts to marine ecosystems within the next hundred years.
Here’s the scintillating science behind it all: In the ocean, carbon dioxide (CO2) reacts with water molecules (H2O) to form carbonic acid (H2CO3). Carbonic acid becomes bicarbonate ions (HCO3-) and hydrogen ions (H+). This increase in hydrogen ions is responsible for reduced pH. Ocean life is sensitive to even the slightest changes in pH levels, and any drop in pH will affect the ability of marine organisms to grow and reproduce.
In addition, some of the hydrogen combines with carbonate to form more bicarbonate, decreasing the concentration of carbonate in seawater. The increasing acidity and the changes in ocean chemistry that ensue make it more difficult for certain marine creatures to survive. These organisms use carbonate, combined with calcium, to form their exoskeletons (phytoplankton, shrimp, crabs, lobsters), their shells (snails, squid, scallops, octopi), or other structures.
Some of those “other structures” are coral reefs, which provide one of the richest habitats on Earth. Can you imagine South Florida without its reef?
Even seemingly insignificant changes in ocean acidity can have dramatic impacts on marine life and cause a ripple effect throughout the food chain. Sometime before the year 2100, the surface of the ocean will become corrosive to the shelled marine organisms here in South Florida and around the world. When shelled organisms are affected by ocean acidification, larger species that feed on those organisms may decline in number. Likewise, our coral reefs may decline due to increasing ocean acidity, resulting in a loss of habitat for thousands of species. All of this means less fish and shellfish available for human consumption.
Like climate change, ocean acidification is a growing global problem that will not solve itself and will only intensify with continued CO2 emissions. If ignored, it will be at our peril.
We live in a world detached of consequence. Like the ocean, I too have grown sour at our society’s blithe disregard for the planet. So, in lieu of more scientific data or chemical equations, I want to close with one simple, universal truth: All living things are connected.
Leopoldo Llinas, Miami’s Community Newspapers, 19 May 20174. Article.