Global warming has become a major concern for the world because of its broad impact on various aspects of life, including marine ecosystems. Rising sea surface temperatures are one of the most striking consequences resulting from global warming. This process will change the dynamics of marine ecosystems, affecting the lives of organisms and ecological balance. First, higher temperatures can result in coral bleaching. Coral bleaching occurs when water temperatures increase, causing the symbiotic algae that provide color and nutrition to coral to disappear. Without this algae, coral reefs lose their color and become susceptible to disease. Loss of coral reefs will result in a decrease in biodiversity because many species depend on reefs as habitat. Second, increasing water temperatures cause changes in ocean currents. Ocean currents play an important role in distributing heat, nutrients and plankton in the ocean. Changes in currents can disrupt fish migration patterns, impacting the fishing industry and food security of coastal communities. Fish that depend on certain temperatures to reproduce may face difficulties in adapting to rapid changes. Furthermore, global warming also affects sea levels rising due to melting of polar ice and thermal expansion. Coastal areas become more vulnerable to erosion and flooding. Mangrove and brackish habitats in coastal areas are decreasing, which reduces protection against natural disasters. This has major consequences for the species that depend on these ecosystems as well as local communities that depend on marine resources for their livelihoods. Water quality is also affected by climate change. Warmer temperatures increase the likelihood of toxic algae blooms, which can cause red tides and affect ocean health. This harmful algae can produce toxins that harm marine life and humans alike. Consuming contaminated seafood can have serious health impacts on humans. Ocean acidification, due to the absorption of CO2 by seawater, is also a direct impact of global warming. Rising CO2 levels cause ocean pH to decrease, potentially destroying organisms with shells, such as molluscs and crustaceans. A decline in the population of these organisms will affect the food chain in the marine ecosystem, disrupting the existing balance. These changes require attention and action from various sectors to mitigate their negative impacts. Handling can be done through reducing greenhouse gas emissions, protecting critical marine ecosystems, and promoting sustainable fishing practices. Public education and awareness are also important to encourage collective action in facing these challenges. By directing attention to protecting marine ecosystems, we can help maintain the balance of nature and support the survival of living creatures in it.