Glaciation is a process where large areas of the Earth's surface become covered by ice sheets and glaciers. This usually happens during periods of colder climate, known as ice ages, when temperatures drop significantly. As the ice accumulates, it can reshape the landscape, carving out valleys and creating features like fjords and moraines. During glaciation, the movement of ice can also affect sea levels. When ice sheets grow, they store vast amounts of water, causing sea levels to fall. Conversely, when the ice melts, as seen in the current effects of climate change, sea levels rise, impacting coastal regions and ecosystems around the world, including places like the Arctic and Antarctica.