Purpose: With the increase in industry and the augmentation of the human impact on the environment, much carbon dioxide is released into the atmosphere, which is then absorbed by the oceans. Two chemical effects of increased carbon dioxide production are acidity and hypoxia. The individual effects of increased hydrogen ion production as well as an augmentation of hypoxia and the resulting temperature increase are not completely known. The effects of the comparison of different aspects of ocean acidity and different time period levels have not been previously explored, and the resulting trends are unknown. Hypothesis: As the pH and temperature are decreased, the corresponding effects of ocean acidity on Tigriopus californicus will be greater. Acidity will have a more severe impact than temperature. Materials/Methods: An ultimate ocean environment was created to represent and mimic Earth's ocean environment in order to keep several variables constant (temperature, salinity, and oceanic mineral content) as to be used for preliminary tests, pH integration tests, and temperature integration tests. In order to determine the importance of the inclusion of food as a constant, a preliminary test was set up to compare the effects of the inclusion of food on Tigriopus californicus. Because viability was not affected by the integration of food, food supply did not need to be controlled and taken into account throughout the rest of the study. Sodium bicarbonate, sodium hydroxide, and hydrochloric acid were used as acids and bases to attain desirable pH levels of the seawater solution representing different time periods in Earth's history and future: the Great Dying level (pH=3.4), the Future (+100 years from present) level (pH=7.9), the Present-Day level (pH=8.2), and the Pre-Industrial level (pH=8.4). Each level was designated an individual test tube in the experiment, and a constant number of Tigriopus californicus organisms (5) were exposed to a constant volume (10 mL) of each pH-manipulated seawater solution. The organisms were also exposed to temperature-manipulated levels that correspond with present (10°C) and Great Dying (40°C) temperature levels by placing organism-containing test tubes in an incubator and refrigerator. Results: The acidity tests were representative of the corresponding pH levels, and the Great Dying acidity level produced a 0 % survival rate by 72 hours, while the Present, Pre-Industrial, and Future levels produced survival rates in-between those of the control (100 % survival rate until 360 hours) and the Great Dying level. The Great Dying and temperature level proved to affect a 0% survival rate by 24 hours, while the present level was consistent with the control level (100% survival rate). Conclusion: A trend can be determined as to the effects of temperature and acidity on Tigriopus californicus that proves that temperature has a more severe effect on Tigriopus californicus than acidity. Both aspects prove, however, the detrimental qualities of ocean acidity on marine organisms and their ecosystems.