Global warming has become a major concern throughout the world, especially for marine ecosystems. As sea surface temperatures increase, the negative impacts on marine life are becoming increasingly apparent. One of the impacts is coral reef bleaching. As a habitat for various species of fish and marine organisms, coral reefs are very sensitive to temperature changes. As water temperatures rise, corals become stressed, and in some cases, may die, resulting in biodiversity loss. Changes in temperature also affect the migration patterns of fish species. Fish such as salmon and tuna are starting to move to colder areas in search of more suitable habitat. This not only disrupts local ecosystems, but also impacts the global fishing industry. When target species move, fishermen must adapt to search for new resources, which can disrupt the ecosystem in the new location. Meanwhile, increasing carbon dioxide (CO2) content in the atmosphere also causes ocean acidification. Sea water absorbs CO2, which then forms carbonic acid. This process reduces the pH of seawater, harmful to organisms such as molluscs, crustaceans and plankton that rely on calcium carbonate to form their shells. The decline in populations of these species impacts the food chain, which in turn impacts the health of the entire marine ecosystem. In addition, global warming exacerbates extreme weather phenomena, such as storms and floods. Stronger storms threaten coastal areas and affect mangrove and seagrass ecosystems, which serve as carbon capture and habitat for many species. The existence of this ecosystem is very important for mitigating the impacts of climate change by storing carbon in the soil. Climate change also affects the distribution of nutrients in the ocean. Higher temperatures can affect seawater circulation patterns, meaning that nutrient supplies to productive areas such as upwellings can be reduced. The impact can be seen on the biological productivity of marine ecosystems, which influences the ocean’s ability to support life. We also cannot ignore its impact on marine biodiversity. Species that are unable to adapt quickly to environmental changes will be threatened with extinction. This not only harms the ecosystem, but also threatens the sustainability of the livelihoods of communities that depend on marine resources. Finally, global warming affects human health through impacts on marine ecosystems. Decreasing the quality and quantity of marine resources can have an impact on food availability, especially for countries that depend on marine products as the main source of protein. Reducing the impact of global warming on marine ecosystems must be a priority for humanity to support ecosystem balance and the sustainability of marine resources in the future.