You may remember Elizabeth Kolbert as author of the extensive New Yorker series on climate change that was Hal's Pick in May of 2005. She also wrote about the ways in which ice core samples disclose the history of the atmosphere; that article was Hal's Pick in January of 2002. This month, she continues her fine work on this subject with a disquieting piece about the consequences of increased carbon dioxide concentrations for the chemistry of the ocean and the fate of marine life. About half of all of the carbon dioxide that humans have emitted since the beginning of the 19th century has been absorbed by the world's oceans. Were it not for this sink, the concentration of would already be approaching 500 ppm. There is no way whatsoever that the concentration will not continue to increase for another fifty or more years, even if the most stringent and Draconian policies were to be adopted (and there is no sign of that!) Kolbert describes the research on impact of more atmospheric carbon dioxide on pteropods, corals, the pH of the ocean, and photosynthesis by marine animals. The news is not bad; it is terrible. The "simple" equilibrium between carbonate, bicarbonate, and carbonic acid - the one that we all teach about in introductory chemistry courses - may be the chemical reaction that determines the fate of the world.