International Journal of Marine Science, 2024, Vol.14, No.2, 102-110 http://www.aquapublisher.com/index.php/ijms 103 hope to provide more scientific and reasonable suggestions and strategies for ocean management and protection under global climate change, and provide reference and guidance for future policy formulation and environmental governance. 1 Causes of Sea Level Rise 1.1 Rising global temperatures and melting polar ice caps Rising global temperatures are a major challenge facing the world today. It directly leads to the accelerated melting of polar ice caps, a phenomenon that has had a profound impact on the earth's natural environment and human society. With the emission of large amounts of greenhouse gases, especially CO2, the average temperature of the earth continues to rise. This increase in temperature not only affects the Earth's climate patterns, but also causes the polar regions, especially the ice caps in the Arctic and Antarctic, to melt at an unprecedented rate (Wei et al., 2023). The melting of polar ice caps contributes significantly to global sea level rise. As ice sheets gradually merge into the ocean, global sea levels rise year by year, threatening the ecosystems and human settlements in coastal areas. Rising sea levels have led to more frequent coastal flooding, eroding coastlines, destroying habitats, affecting fishery resources, and also increasing the risk of storm surges, posing a threat to coastal cities (Figure 1). Figure 1 The areas affected by Sea level rise and the percentage of the population that are at risk (Elneel et al., 2024) Melting polar ice caps also affect the global climate system. Ice and snow have high reflectivity and can reflect most solar radiation, but when the ice caps melt and expose darker seawater or land, these areas will absorb more solar energy, exacerbating the regional and global greenhouse effect. The melting of the Arctic ice caps also affects the global ocean circulation system, because the injection of fresh water changes the salinity and density of seawater, which in turn may affect global climate patterns and weather systems. 1.2 The physical process of thermal expansion and contraction of sea water Thermal expansion and contraction of seawater is a basic physical process, which describes the phenomenon that the volume of seawater changes with temperature changes. This process plays a key role in Earth's climate system and sea level changes. When the temperature of seawater rises, the movement of water molecules accelerates, causing the average distance between molecules to increase, which in turn causes the volume of seawater to expand. This is the so-called "thermal expansion" phenomenon. On the contrary, when the temperature of seawater decreases, the movement of water molecules slows down, the average distance between molecules decreases, and the volume of seawater shrinks accordingly. This is the "cold shrinkage" phenomenon (Su et al., 2024). This process has important consequences for sea level rise on a global scale. As global temperatures continue to rise, the oceans absorb large amounts of heat, causing seawater temperatures to rise and seawater volumes to
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