The Other CO2 Nasty

 

It’s no secret that methane (CH4) and carbon dioxide (CO2) are the mainstay of greenhouse gasses. Whether the result of burning fossil fuels or the release of methane trapped in melting permafrost (tundra), the surfeit of these emissions since the Industrial Revolution is mankind’s toxic “gift”: climate change, that lovely global warming wreaking so much havoc all over this planet. But the excess flood of carbon dioxide into the atmosphere, which used to be absorbed so much more by the chlorophyl green of plant life, has other nasties that most people do not know. The slow poisoning of our oceans by increasing seawater’s relative acidity.

“‘Ocean acidification refers to the whole suite of chemical changes that happen in the ocean when you start decreasing pH in ocean waters,’ says Dr. Catherine V. Davis, Yale Institute for Biospheric Studies Gaylord Donnelley Postdoctoral Associate in the Department of Earth and Planetary Sciences… Davis explains that as you add carbon dioxide to a liquid, it will decrease the pH and start to form acids.

“‘Think about the difference between carbonated water and tap water,’ Davis says. ‘The carbonated water has carbon dioxide in it and forms acid, which gives you that tingling sensation on your tongue. A similar thing is happening in the ocean, with obviously some larger scale changes associated.’” Yale Sustainability, September 21st.

Our Environmental Protection Agency explains the impact of increased ocean acidity on sea life: “By releasing carbon dioxide to the atmosphere, humans are rapidly altering the chemistry of the ocean and affecting marine life. The acidity of the ocean has increased by about 25% since before the Industrial Revolution, greater than any other time within the last two million years. Given the speed at which humans are altering ocean chemistry, marine plants and animals may not have time to adapt or migrate as they did in the past to cope with changes to ocean chemistry over the history of the Earth.  

“As a consequence of acidification, marine life face a two-fold challenge: decreased carbonate availability and increased acidity. Laboratory studies suggest changing ocean chemistry will 1) harm life forms that rely on carbonate-based shells and skeletons, 2) harm organisms sensitive to acidity and 3) harm organisms higher up the food chain that feed on these sensitive organisms. However, we do not yet know exactly how ecosystems will be impacted.”

Want a little more detail: “Dr. Ellen Thomas, Senior Research Scientist in the [Yale University] Department of Earth and Planetary Sciences, further explains that the ocean is not turning into acid, per say. Instead, it is just becoming less basic… ‘Remember the pH scale from elementary school,’ Thomas says. ‘There is a number seven in the middle. Everything lower than 7 is acid, and everything higher than 7 up to 14 is basic. Before human activity, the ocean was 8.2 on that logarithmic scale, and we have now moved down by one pH unit to 8.1. The ocean is still basic, as it is still to the right of that value seven, but it has moved towards this direction of more acid – which is very serious.’” Yale Sustainability.

The EPA tells us which organisms are impacted the most: “Many ocean plants and animals build shells and skeletons out of two chemicals that exist in seawater, calcium and carbonate. Organisms combine calcium and carbonate to form hard shells and skeletons out of the mineral calcium carbonate. Therefore, the plants and animals that use calcium carbonate for structure and protection are called calcifying organisms. Increased acidity slows the growth of calcium carbonate structures, and under severe conditions, can dissolve structures faster than they form…

“Just like humans, marine organisms require optimal conditions inside. their bodies to stay healthy. If the acidity of seawater is beyond the optimum range for that organism, its body must use more energy to maintain healthy body fluid chemistry. Organisms can often compensate when faced with increased acidity, but this comes at the expense of using energy to grow critical body parts like muscle or shell. For example, scientists have found that mussels, sea urchins, and crabs start to dissolve their protective shells to counter elevated acidity in their body fluids. So even if an organism can adjust to survive increasing acidity its overall health can be impaired.

“Many marine fish and invertebrates have complex life cycles. They spend their early lives as larvae while they develop and disperse to distant areas on ocean currents. Larvae are very small, which makes them especially vulnerable to increased acidity. For example, sea urchin and oyster larvae will not develop properly when acidity is increased. In another example, fish larvae lose their ability to smell and avoid predators. The vulnerability of larvae means that while organisms may be able to reproduce, their offspring may not reach adulthood.”  

We can see and feel the force of hurricanes, the devastation of wildfires, the damage of desertification in some areas with storm surges and flooding in others. All exacerbated by climate change. But what we cannot readily see is the undersea damage to marine life that just might lead to irreversible extinction of so many species. We are killing ourselves as well.

I’m Peter Dekom, and that climate change “red alert” to humanity is so much more than most people realize.