Imagine that a recently discovered pollutant prevented trees from forming leaves. Every April, buds would spring from the branches, and kids on their way to school would point to the tiny shoots of green and pink. But as the leaves fleshed out further and began to photosynthesize, an invisible vapor would choke and corrode them. The tree would eventually just wear away, its bark falling off in chunks.
It is not an exaggeration to say that something similar is happening right now—yet in Earth’s oceans, and so outside of most Americans’ daily view. A fundamental chemical change in the oceans has made marine waters less hospitable to any animal that builds a hard shell or a skeleton. In some places, hatcheries report that oyster larvae are dying by the billions, corroded away before they can grow. The chemistry is already affecting corals, clams, and the zooplankton that form the basis of the marine food chain.
The phenomenon is ocean acidification, and it is caused by the same carbon dioxide that is forcing the planet to warm via the greenhouse effect. Though it much less understood, ocean acidification may cause as much harm as global warming, as it’s a recognized threat to the nation’s (and the planet’s) fisheries, marine ecology, and economic health. Yet no government in the United States—not the federal Environmental Protection Agency, none of the 50 states—regulates ocean acidification like they would another water pollutant.