Long-term impacts of global temperature stabilization and overshoot on exploited marine species

Abstract. Global warming alters ocean conditions, which can have dramatic consequences for marine species. Yet, the centennial-scale effects and reversibility of habitat viability for marine species, particularly those that are important to fisheries, remain uncertain. Using the Aerobic Growth Index, we quantify the impacts of warming and deoxygenation on the contemporary habitat volume of 46 exploited marine species in novel temperature stabilization and overshoot simulations until 2500. We demonstrate that only around half the simulated loss of contemporary (1995–2014) habitat volume is realized when warming levels are first reached. Moreover, in an overshoot scenario peaking at 2 °C global warming before stabilizing at 1.5 °C, the maximum decrease in contemporary habitat volume occurs more than 150 years post-peak warming. Species’ adaptation may strongly mitigate impacts depending on adaptation rate and pressure. According to our study, marine species will be affected for centuries after temperature stabilization and overshoot, with impacts surpassing those during the transient warming phase.