Frank Valoy- Chapter 6: The Sea Around Us

             Elizabeth Kolbert begins chapter 6 by talking about her experience in Ischia. In Ischia, she swam with biologists Jason Hall-Spencer and Maria to see vents on the ocean floor, which were caused by a volcanic eruption. They noticed carbon dioxide bubbles coming out of these vents.
             Kolbert mentions the Industrial Revolution being a time of urbanization where humans began to pollute the air by releasing greenhouse gases into the atmosphere. She explained that ever since then, the amount of pollution being released into the air has increased and that it’s expected to increase the global temperature between 3.5 to 7 degrees Fahrenheit, triggering world-altering events (Pg. 113). (R) This suggests that humans are slowly changing the Earth’s environment in many negative ways, connecting to the theme “Humans alter natural systems”. I feel that this part of the chapter is implying that us humans today must change our way of life so that we’re not the only ones benefiting.
             It was found out that many greenhouse gases being released into the air, especially carbon, are being absorbed by the ocean, making it more acidic. This affects many marine species and Hall-Spencer stated, “...They’ve [Marine species] just got to tolerate what’s happening outside, and so they get pushed beyond their limits” (Pg.116). (E) I found this quote very significant because many species suffer the consequences of humans’ actions and they have no choice but to.
             Hall-Spencer did an experiment where he observed different marine species from different locations away from the vents of the seafloor and near them. He noticed that he saw fewer species the closer he got to the vents, which have a pH of 7.8. It was concluded that the higher the acidity, the fewer species present in the ocean.
             Ulf Riebesell, a biological oceanographer, also concluded that the higher the ocean acidification, the lower the biodiversity. He also found out that smaller organisms such as plankton tend to survive this increase in acidity. Kolbert mentioned that this was a cause of the 2nd out the Big Five extinctions during both the end-Permian and end-Cretaceous eras. An increase acidity of the ocean is also creating holes in the shells of calcifiers.
             Overall, the message of chapter 6 is that the Anthropocene is a time where humans are dominating the environment and harming it with high levels of pollution, leaving a legacy of destruction.