Global warming has a significant impact on marine ecosystems around the world, and its effects can be seen in many aspects. The most prominent phenomenon is an increase in sea surface temperature. This increase in temperature not only affects marine life, but also disrupts existing ecosystem cycles. For example, coral reefs, an important habitat for many fish species, are starting to experience bleaching due to rising water temperatures. In addition, global warming also causes an increase in CO2 levels in the air, which dissolves in seawater and causes a decrease in seawater pH, a process known as ocean acidification. Under these conditions, it becomes more difficult for seafood such as shellfish and sponges to form their shells. This impacts the marine food chain, as species that depend on these organisms will face a shortage of food sources. Changes in ocean current patterns and increased frequency of storms are also significant impacts of global warming. Disrupted flows can affect water temperature and salinity, which in turn impacts species distribution. Some species may begin to move to new, more comfortable areas, while others may become endangered due to their inability to adapt. Rising sea levels due to melting polar ice also threaten coastal ecosystems. Areas such as mangroves and seagrass which function as buffers for marine communities are starting to erode. This loss of habitat not only threatens the flora and fauna that depend on these ecosystems, but also reduces protection for coastal areas from erosion and storms. No less important, socio-economic impacts also play a role in the impact of global warming on marine ecosystems. Communities who depend on fisheries and marine tourism are starting to feel the impact. A decline in fish numbers could lead to a food and economic crisis, especially in countries that rely heavily on marine resources. Human activities, such as overfishing and pollution, further exacerbate the effects of global warming. In many cases, marine ecosystems cannot recover due to these dual pressures. Sustainable management and environmental protection policies are becoming increasingly important to reduce the negative impacts experienced by marine ecosystems. Global initiatives to reduce greenhouse gas emissions, such as the Paris Agreement, show promise in addressing the issue of global warming. However, awareness and concrete action from individuals, communities and governments are urgently needed to protect marine ecosystems from the increasingly worrying impacts of warming. By taking preventative and mitigation measures, we still have a chance to protect precious marine ecosystems and ensure the survival of life within them.