by J.P. Rose
While many Americans have heard that carbon dioxide emissions are a major cause of climate change, carbon dioxide also contributes to a lesser-known but similarly serious problem. That problem is ocean acidification, and it threatens not only the vibrant beauty and biodiversity of Earth’s coral reefs, but also the livelihoods of millions of people. A new report by an international panel of scientists warns that the health of the oceans—and particularly of corals—is slipping faster than even pessimists had earlier predicted, and that mass extinctions of fish and coral may occur unless humans take action.
I first became aware of the threats facing coral reefs after discovering the addictive sport of snorkeling. Over the past five years, I have found opportunities to snorkel in the Bahamas, Caribbean, and Mediterranean. During my underwater adventures, I have witnessed some colorful coral reefs that are bursting with hundreds of different fish species, and other less fortunate reefs that are grayish white and home to only a few species.
The grayish white of these less fortunate reefs reflects bleaching, which is caused by ocean acidification and increased water temperatures from climate change. Ocean acidification is the term used for declining levels of pH in the upper layers of the ocean due to the absorption of increased levels of atmospheric carbon dioxide. The oceans are actually a huge carbon “sink” that absorb about forty percent of the carbon dioxide emitted by human activities. Yet, allowing the oceans to continue to act as a huge sponge for human-caused carbon dioxide emissions is unsustainable. When carbon dioxide dissolves in the ocean, it changes into carbonic acid, which lowers the pH and increases the acidity of the ocean. Heightened ocean acidity dissolves carbonate minerals such as aragonite that are essential to the growth of coral skeletons, a process known as calcification.
Scientists at the Carnegie Institute for Science predict that this process will make 98% percent of present-day reefs unable to grow by 2050, if current carbon dioxide emission trends continue. Unlike climate change forecasts, which do involve some degree of uncertainty, researchers have already verified and documented the process of ocean acidification due to absorption of anthropogenic (human-caused) carbon dioxide. Unless humans substantially curb their carbon dioxide emissions, entire ecosystems including coral reefs may be gone within a generation.
The decline of coral reefs profoundly impacts ocean ecosystems and the people who depend upon them. Known as the “rainforests of the sea,” coral reefs are home to thousands of fish species, and act as a nursery for juveniles. Areas with degrading coral are already experiencing reduced numbers of fish as well as reduced biodiversity, such as in Papua New Guinea, where approximately half of all fish species studied declined by over fifty percent. Moreover, half a billion people depend on coral reefs to some degree for their food, income, or coastal protection while thirty million people are entirely dependent upon coral reefs for their livelihood. In addition, the natural beauty of coral reefs and their colorful inhabitants lures many people (myself included) to countries surrounded by coral reefs, which these countries’ economies rely upon for tourism.
Notwithstanding the protestations of a few organizations funded by the oil industry  and the slanted reporting by some media sources , there is scientific consensus that atmospheric carbon dioxide is causing ocean acidification  as well as climate change. Even though predicting the exact amount of damage to reef ecosystems and the broader ocean is impossible, the weight of the evidence indicates we should utilize the precautionary principle and work together to reduce carbon dioxide emissions (for example, through switching to clean energy sources as a nation and individually). As the richest and most powerful nation on Earth, the United States has a moral imperative to take the lead in preserving the natural resources and technicolor biodiversity of the oceans.
J.P. Rose is a legal intern at CRS and a rising third-year student at Santa Clara University School of Law.
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