<human>:  What are the effects of global warming on sea levels?
<bot>: The primary effect of global warming on sea levels is that they are rising. The increase in the Earth's average temperature causes thermal expansion of seawater and the loss of land-based ice due to melting, both of which contribute to rising sea levels. This leads to coastal flooding and eroding shorelines. It also increases the risk of shoreline flooding due to high waves and storm surges. In addition, as sea levels rise, it increases the salinity of coastal estuaries, threatening aquatic species and habitats.