It is mainly about the thermal expansion of sea water, as the ocean warms, the sea level is rising. Global warming will cause the melting of glaciers at the earth's north and south poles, which is a major cause of sea level rise. The direct effects of sea level rise include three aspects. The first is lowland flooding: such as higher levels in the UK in response to climate warming. Global warming is causing sea levels to rise and the frequency of storms to increase, forcing the government to strengthen the dam for flood control. According to statistics released by British officials, over the past 20 years, due to the Thames River's water levels rising with global warming, local government agencies have subsequently flooded the dam 88 times. In order to ensure the safety of life and property of the people of London. The second point is the increase in salt in surface and groundwater. The effect of urban water supply. The third point concerns the damage caused by tourism and the influence on the lives of residents of the coasts and islands, which are in danger. If the polar ice caps were to melt, economically developed and densely populated coastal areas would be swallowed up by the sea. The coastal cities of Maldives, Shanghai, Venice, such as Hong Kong, Tokyo, New York, Bangkok, Rio de Janeiro and Bangladesh, Holland, Egypt and other countries will also be present