Elizabeth Kolbert reports on the impact of carbon-dioxide emissions on the ocean, which is resulting in “ocean acidification” and threatening the entire marine ecosystem (“The Darkening Sea,” p. 66). Kolbert explains that acidification is caused by the decrease in the ocean’s pH level due to its uptake of carbon dioxide, or CO2, noting that the ocean, which covers seventy per cent of the earth’s surface, absorbs and releases gases from and into the atmosphere at roughly equal rates. “But change the composition of the atmosphere, as we have done, and the exchange becomes lopsided: more CO2 from the air enters the water than comes back out,” she writes. Kolbert reports that humans have already pumped some hundred and twenty billion tons of carbon into the oceans, to produce a .1 decline in surface pH, which represents a rise in acidity of roughly thirty per cent. “This year alone, the seas will absorb another 2 billion tons of carbon, and next year it is expected that they will absorb another 2 billion tons,” Kolbert reports. “Every day, every American, in effect, adds forty pounds of carbon dioxide to the oceans.” Kolbert writes, “Because of the slow pace of deep-ocean circulation and the long life of carbon dioxide in the atmosphere, it is impossible to reverse the acidification that has already taken place. Nor is it possible to prevent still more from occurring. Even if there were some way magically to halt the emission of CO2 tomorrow, the oceans would continue to take up carbon until they reached a new equilibrium with the air. . . . Humans have, in this way, set in motion change on a geological scale. The question that remains is how marine life will respond.”
The New Yorker, 20 November 2006. Web site.
