Global climate change is a crucial issue that affects various aspects of life, including marine ecosystems. The oceans absorb nearly 30% of the carbon dioxide (CO2) produced by human activities, with profound consequences for the marine environment. In this context, the impacts of climate change on marine ecosystems include increasing water temperatures, ocean acidification, and habitat loss. Rising ocean temperatures have a direct impact on marine species. Higher temperatures can cause species migration, where fish and other marine organisms move to cooler areas. For example, tuna populations normally found in tropical waters are now moving to more northerly locations, affecting global fisheries patterns and economic impacts on fishing communities. In addition, ocean acidification, which occurs due to the absorption of CO2, has serious consequences for organisms that have shells, such as corals and mollusks. A decrease in seawater pH disrupts their calcification process, which can result in damage to coral habitats. Coral reefs, which are the epicenter of marine biodiversity, are threatened by this acidification, potentially reducing the refuge for many species. Habitat loss is another problem that must be faced. Warming sea water and increased frequency of storms affect mangrove and seagrass ecosystems. This area is very important as a carbon filter and refuge for various marine fauna. Damage to mangroves and seagrasses not only reduces biodiversity but also affects the ecosystem’s ability to support local life. Furthermore, climate change is contributing to an increase in the frequency and intensity of extreme weather events, such as hurricanes and floods. These events can damage coastal infrastructure, disrupt ecosystems, and reduce water quality. The impact is felt on ecosystem health, changing the social and economic nature of communities that depend on marine resources. Climate change could also worsen marine pollution problems. With reduced salinity due to increased freshwater pollution, marine organisms are becoming more susceptible to disease and environmental stress. This can lead to a decline in species populations that are vital for ecosystem balance. Changing weather patterns also impact the reproductive cycles of fish and other marine organisms. Warmer temperatures may speed up the reproduction of some species, but they could also put others at risk of extinction. This imbalance in the food chain creates challenges for sustainable fishing. So, it is very important to increase awareness and action on climate change and its impact on marine ecosystems. Conservation efforts, further research, and policies that support maintaining marine ecosystems are very important to support the balance and health of the ocean in the future. Changes need to be made globally by involving various parties so that marine ecosystems can recover and adapt to the existing challenges of climate change.