Ocean Acidification

A new study by Columbia University is calling attention to what has been deemed “the other carbon dioxide problem”–ocean acidification.
Global warming has long been making headlines, but a new study by Columbia University is calling attention to what has been deemed “the other carbon dioxide problem”–ocean acidification. The phenomenon of ocean acidification occurs when too much carbon dioxide is released into the atmosphere (2010 marked the highest CO2 emissions in history). The oceans draw excess CO2 from the air into the water. The CO2 reacts with the water to form hydrogen-rich carbonic acid, which over time is neutralized by what Dr. Cliff Law, an oceanographer with the National Institute of Water and Atmospheric Research in New Zealand, calls the ocean’s “very clever buffering system”: calcium carbonate. But if too much carbon dioxide enters the ocean too quickly, it can deplete the alkaline carbonate that corals, mollusks and some plankton need for reef and shell-building.

According to the researchers, who studied hundreds of paleoceanographic records, today’s rate of ocean acidification is similar to only one period in the last 300 million years: the Paleocene-Eocene Thermal Maximum (PETM). During the PETM period, global temperatures rose five degrees Celsius in response to massive emissions of CO2 and other heat-trapping greenhouse gases into the atmosphere from volcanoes and other natural sources. The deep ocean acidified so much that nearly all the calcium carbonate sediment completely dissolved. One of the study’s authors, Lee Kump of Pennsylvania State University, points out that the greenhouse gases were released during the PETM period at only 10% of the rate by which they are building up in the atmosphere today.

“What we’re doing today really stands out in the geologic record,” said lead author Bärbel Hönisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory. “We know that life during past ocean acidification events was not wiped out–new species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care about–coral reefs, oysters, salmon.”

In this clip, Dr. Law explains the science behind ocean acidification, its dire consequences to all marine life and what scientists are looking into to halt the process.