What's the difference between melting sea ice and melting land ice on sea levels?

Sea ice is already part of the ocean, so when it melts, it doesn't add more water to the seas, similar to how a melting ice cube in your drink doesn’t make it overflow. On the other hand, land ice—found in glaciers and ice sheets on continents—sits on land. When this ice melts, the water flows into the ocean, increasing the overall water volume and causing sea levels to rise. This is why scientists are particularly worried about the melting of large ice sheets in Greenland and Antarctica, as they contain enough land ice to significantly raise global sea levels and impact coastal communities.