Glaciers are large masses of ice that form on land from compacted snow and slowly deform and flow due to their own weight. They are found on every continent except Australia and cover about 10% of Earth's land. The three largest glaciers are located in Central Asia, North America, and the Arctic Islands. Glaciers are threatened by global warming, which causes them to melt and sea levels to rise, potentially flooding coastal regions and disrupting ecosystems that depend on glacial meltwater. Reducing greenhouse gas emissions and developing alternative energy sources can help address the issues caused by melting glaciers.