It all seemed so convenient: As our smokestacks and automobile tailpipes spewed ever more carbon dioxide into the air, the oceans absorbed the excess. Like a vast global vacuum cleaner, the world’s seas sucked CO2 right out of the atmosphere, mitigating the dire consequences of global warming and forestalling the melting of glaciers, the submergence of coastlines, and extremes of weather from floods to droughts. So confident were we in the seas’ seemingly limitless capacity to absorb our gaseous waste that, by the turn of the millennium, the United States, Germany, and Japan were actually proposing to compress CO2 from power plants into a gooey liquid and pipe it directly into the abyss.
The first tests of the plan were an eye-opener. When the compressed material was introduced into laboratory tanks, the spines of sea urchins and the shells of mollusks dissolved. Surprised, researchers launched studies to see how marine animals in laboratory tanks and in the wild would fare with CO2 concentrations much lower than those in the original tests. They were stunned. “We found that mere absorption of CO2 from the atmosphere into the ocean was enough to harm marine creatures,” says Ken Caldeira, a chemical oceanographer now at the Carnegie Institution of Washington in Stanford, California.
The problem was that, having swallowed hundreds of billions of tons of greenhouse gases since the start of the Industrial Revolution, the oceans were becoming more acidic. And not just in a few spots. Now the chemistry of the entire ocean was shifting, imperiling coral reefs, marine creatures at the bottom of the food chain, and ultimately the planet’s fisheries.
In 2003 Caldeira reported these findings in the journal Nature, coining the term “ocean acidification.” One might think the news would spread around the world with the speed and force of a tsunami. But scientific discoveries take time to be digested and disseminated. Only recently have the far-flung implications of this development begun to register beyond the rarefied sphere of marine biologists.
“It’s the most profound environmental change I’ve seen in my entire career, and nobody saw it coming,” says Thomas E. Lovejoy, a biologist and president of the H. J. Heinz III Center for Science, Economics and the Environment in Washington, D.C.
