Estimation of individual ocean acidification footprints

Abstract:

The global ocean is acidifying at an alarming rate due to human activities. Unfortunately, for many people, ocean acidification “the other carbon dioxide problem” is still an unfamiliar concept. Unlike climate change much of humanity does not know about ocean acidification at all. Over the last one hundred years, the ocean has acidified by 26% (Licker et al., 2019), with global ocean pH dropping from 8.2 to 8.1. Without significant reductions in anthropogenic CO₂ emissions, H⁺ concentrations in the ocean are expected to rise by 150% by the year 2100. Despite the dramatic chemical changes in the ocean and the substantial current and future projected global ecological and economic impacts of OA, the lack of OA impacts in many places leads to little understanding, knowledge, or concern about OA among the general public globally. Furthermore, the lack of education surrounding OA creates a greater risk for coastal communities, by reducing their adaptive capacity. Here, to help address this need, we build upon the widespread use of the carbon footprint concept to motivate individual climate action. Using the CO2SYS program developed to calculate carbonate system parameters, we estimate the ocean and coastal acidification footprint for individuals living in different regions of the planet, based on CO₂ emissions and contributions to nutrient loading that drives coastally-enhanced acidification. OA footprints are given in units of ∆pH for an Olympic sized swimming pool of surface ocean water globally ­– and locally, given local coastal alkalinity and temperature variability. We discuss the use of individual action motivation through the “footprint model” and its applicability to ocean and coastal acidification literacy, mitigation and adaptation.