The flames of ocean acidity
By Matthew Huelsenbeck
20 July 2012 The age of fossil fuels has changed the oceans dramatically. What many might not know is that the oceans absorb about one-third of all human-caused carbon dioxide emissions. And while this has saved us from even more rapid climate change, few people realize the true effect this has had on our seas. The recent heat waves, droughts, floods and super derechos are only a fraction of the extreme weather we could expect to see if the oceans weren’t around to help us out. But this grand favor the ocean has done to slow climate change has come at a cost to ocean health. The absorption of carbon dioxide from fossil fuels has substantially altered the ocean’s basic chemistry. In the hundred plus years since the Industrial Revolution, ocean waters have become, on average, 30 percent more acidic. Ocean acidification, or “osteoporosis of the sea” as some are calling it, threatens animals like oysters, mussels, clams, corals, and tiny marine snails called pteropods that use calcium carbonate to form their protective shells and skeletons. But it’s not only the small animals that are affected. Rising ocean acidity levels pose substantial threats to marine biodiversity, fisheries, food security and marine tourism. The last time similar changes in the ocean’s chemistry happened more than 200 million years ago, 95 percent of marine life went extinct. The alarms are sounding. Last week, 2,600 top marine scientists signed a consensus statement urging immediate action to limit greenhouse gas emissions in order to save coral reefs and the people who depend on them. But time and again these warnings result in zero action, and the public is still largely unaware of the issue. Because we live on land and don’t experience these chemical changes directly, scientists have had difficulty illustrating what ocean acidification actually looks like – until now. A recent paper published in the journal Science by Nicolas Gruber from the Swiss Federal Institute of Technology in Zurich demonstrates a new way of visualizing how ocean acidification will impact the California coast in upcoming decades. In the animation, the red coloring represents dangerous conditions for marine life, both for aragonite saturation state (left) and pH (right), and the pulses represent seasonal changes. If you keep watching over time, the graphic shows more and more red, almost like there are flames slowly engulfing our coastline. This imagery is alarming to say the least, but thankfully there is a way to stop those flames from rising. If we work to reduce our carbon dioxide emissions dramatically now, we can stop the rising tide of ocean acidification before it’s too late, and we can protect our seas for future generations.
