Your Carbon Footprint and Ocean Acidification OCE2001C Polk State College Introduction The amount of carbon dioxide in the Earth’s atmosphere has steadily increased since the Industrial Revolution. This is bad news, sort of bad news, and more bad news. The bad news is most of this carbon dioxide is the result of our and it contributes to global climate change. The sort of bad news is the ocean can absorb a lot of this carbon dioxide from the atmosphere and store it. This means the ocean is a carbon sink. More bad news is this carbon dioxide can lower the pH of the oceans. As the ocean becomes more acidic, it threatens marine life, particularly marine animals that build an exoskeleton of calcium carbonate such as bivalves and corals. If you recall, from chapter 7 in our text, the pH of the ocean should be slightly basic. If seawater becomes too acidic, the pH drops. A buffer reaction will raise the pH by tying up hydrogen ions. If the pH becomes too high, hydrogen ions are released to lower the pH. At the basic end of the reaction, calcium carbonate can precipitate. There is a video linked to this Dropbox that summarizes the buffer reaction. As the ocean absorbs carbon dioxide from our atmosphere, it lowers the amount of that greenhouse gas in our atmosphere. Gases dissolve more readily in cold liquids. This means that pH changes to the oceans’ surface waters should become apparent more quickly at the poles. Look at Figure 7.13 on page 197 of your textbook. The video, Acid Test, describes how this is happening in the North Atlantic. As previously noted, lowering the pH of the oceans’ surface waters will make it more difficult for animals such as bivalves, snails, and corals to secrete and maintain exoskeletons. Corals are important for many reasons, as are bivalves. According to Scott Doney and Sara Cooley of Wood Hole Oceanographic Institution (WHOI), acidification of the oceans could cause up to $1.4 billion in lost revenue for the seafood industry. The pH of the ocean could drop to 7.8 by the end of this century and the Arctic Ocean could become undersaturated with respect to a type of calcium carbonate called aragonite (Feely, Doney, and Cooley, 2009). This can devastate the calcium carbonate secreting microorganisms that form the base of the marine food chain. References Feely, R.A., Doney, S.C., and Cooley, S.R., 2009. Ocean Acidification: Present Conditions and Future Changes in a High – CO2 World. Oceanography, 22(4), 37-47. www.whoi.edu. Rising acidity levels could trigger shellfish revenue declines, job losses. https://www.whoi.edu/press-room/news-release/rising-acidity-levels-could-trigger-shellfishrevenue-declines-job-losses/ Updated April 18, 2011. Activity 1: Watch the two videos linked to this Dropbox. Activity 2: Calculate your Carbon Footprint using the following calculator: Carbon Emissions Calculator (Lehigh University) Answer the following: 1. The percentages of carbon emissions generated by my activities are ____________from household activities, ____________ from transportation, and _____________ from food. My total annual carbon emissions are _____________ tons. (Find this in upper right corner of page.) 2. Describe how your emissions compare to average U.S. and World emissions. 3. Reflect on the factors that contribute to your carbon footprint. Were you surprised by the activities that had smaller or larger impacts than you expected? What was your reaction to learning your carbon footprint? If more people understood their carbon footprint, do you think anything would change? 4. What do you think would be the impact if more people substantially reduced or eliminated the major contributors to their carbon footprint? Do you think this is feasible? Why or why not? 5. Based on the information from the videos, what implications does a lower the pH of ocean water have for marine organisms that build an exoskeleton of calcium carbonate? Do you think that smaller organisms will be more vulnerable to damage by acidic seawater? If so, what are your reasons? What does this imply for the food chain and the marine ecosystems (think about the phytoplankton)? 6A. Has your perception of issues associated with the increase in carbon dioxide in the atmosphere from human activities and the health of the oceans changed since doing this exercise? Describe how your perception has changed or how it has not changed? 6B. How do you think a decline in the health of the oceans can or will impact or will not impact the well-being of humans?