In this group activity, learners act out key stages of the "ocean carbon cycle" (also known as the "carbonate buffer system") through motions, rearranging blocks and team tasks. Learners will also hypothesize the potential effects on the ocean and coral when variables are changed (e.g. the addition of massive amounts of CO2 and increased water temperature). At least 8 learners are needed to participate in the simulation. This detailed lesson plan includes an introduction, background information related to corals and the ocean carbon cycle, and adaptation suggestions for younger learners. [Activity is publicly available through a web crawler capture on Archive.org.]