Three decades of ocean warming impacts on marine ecosystems: A review and perspective

Ocean warming, primarily resulting from the escalating levels of greenhouse gases in the atmosphere, leads to a rise in the temperature of the Earth's oceans. These gases act as heat-trapping agents, contributing to the overall phenomenon of global warming. In order to gain a comprehensive understanding of how ocean warming impacts marine ecosystems, a thorough literature review was conducted over a span of three decades, involving 2484 initial publications. The systematic literature review screening was facilitated by utilizing Abstrackr's web-based application to efficiently select relevant abstracts, resulting in a final list of 797 publications aligned with the study's objectives. Since the advent of the industrial revolution, greenhouse gas emissions have witnessed an exponential surge, leading to a cumulative increase in atmospheric temperatures at an average rate of 0.08 degrees C (0.14 degrees F) per decade since 1880. Over the past 50 years, the ocean has emerged as a primary heat reservoir, absorbing and distributing the majority of the Earth's warming, with more than 90% of the heat gain occurring within its waters. Between 1950 and 2020, the global sea surface temperature (SST) increased by 0.11 degrees C (0.19 degrees F). The consequences of ocean warming extend significantly to the environment and climate. It induces the expansion of the ocean, alters its stratification and currents, diminishes oxygen availability, elevates sea levels, and intensifies hurricanes and storms. It also affects marine species' physiology, abundance, distribution, trophic interactions, survival, and mortality and can also cause stress and consequences for human societies that depend on impacted marine resources. Ocean warming is projected to increase from 2 to 4 and 4-8 times under climate scenarios Shared Socioeconomic Pathways 1-2.6 and Shared Socioeconomic Pathways 5-8.5, respectively, with an additional 0.6-2.0 degrees C added by the end of the century. We summarize its impacts and detailed negative or positive responses on marine taxonomic groups. We also provide critical information to help stakeholders, scientists, managers, and decision-makers to mitigate and adapt while improving biodiversity conservation and sustainability of marine ecosystems.