Article posted Thursday, July 30, 2015 12:35pm

The Pinatubo eruption in 1991. Photo courtesy of the United States Geological Survey.

It is a fact that our ocean is becoming more acidic, and man-created carbon dioxide (CO2) contributes to the phenomenon. The ocean absorbs 30 to 40 percent of CO2 in the atmosphere, and with increasing levels of this atmospheric gas, the more acidic the ocean becomes. So what are we to do? Wait on technology to save our ocean? What happens is that CO2 dissolved in seawater combines with water molecules to form carbonic acid, which itself dissociates into bicarbonate and hydrogen ions (positively-charged elements, or H+). As more H+ ions are released from chemical reactions between CO2 and water, the ocean becomes more acidic. About 250 million years ago, 90 percent of sea life and two-thirds of all terrestrial plants and animals died, apparently due to volcanic eruptions that threw tons and tons of CO2 into the atmosphere, which in turn caused the ocean to become more like vinegar than pure salt water.

The importance of volcanic activity is the “elephant in the room” in forecasting climate change. Volcanic eruptions of the recent past remind us that man is powerless when a volcano blows its stack and spews poisonous gases, debris, and molten rock into the atmosphere, along with tons of CO2.

In 1815, Mt. Tambora in Indonesia killed 71,000 people, and in 1883, Krakatoa, another Indonesian volcano, smothered 34,000 people when it erupted. In 1991, Pinatubo in the Philippines killed 850 people and caused evacuation of 66,000. As recently as 2010, atmospheric volcanic ash from Iceland’s Eyjafjallajökull volcano caused air space to be restricted over northern Europe. Since it blew through glacial ice, no lives were lost. Researchers now report that two large chambers of volcanic magma rumble beneath Yellowstone Park, which sits in the crater of a supervolcano. This reservoir of sponge-like debris and molten rock is large enough to fill the Grand Canyon many times over. It lies so close to the surface that over the years some of the trails were almost too hot to walk on. When and if the sleeping Yellowstone volcano erupts, our world will change overnight. (The Week, May 1, 2015; unews.utah.edu/news releases; Apr. 24, 2015; pmel.noaa.gov/CO2; whoi.edu/maintopic/ocean acidification; Zeebe & Wolf-Gladrow, 2001, Carbon Dioxide in Seawater…, Elsevier Press, NY, 360 pp; other sources)